Formation of a microvillus, a thin cylindrical membrane-covered projection on the surface of a cell.

Any process that activates or increases the activity of a GTPase.

A process in which a protein is transported to, or maintained in, a specific location in the plasma membrane.

Any process that activates or increases the activity of a GTPase.

The process whose specific outcome is the progression of a blood vessel over time, from its formation to the mature structure. The blood vessel is the vasculature carrying blood.

The characteristic movement of an immature neuron from germinal zones to specific positions where they will reside as they mature.

Any process that increases the rate, frequency or extent of neuron projection development. Neuron projection development is the process whose specific outcome is the progression of a neuron projection over time, from its formation to the mature structure. A neuron projection is any process extending from a neural cell, such as axons or dendrites (collectively called neurites).

The process whose specific outcome is the progression of the brain ventricular system over time, from its formation to the mature structure. The brain ventricular system consists of four communicating cavities within the brain that are continuous with the central canal of the spinal cord. These cavities include two lateral ventricles, the third ventricle and the fourth ventricle. Cerebrospinal fluid fills the ventricles and is produced by the choroid plexus.

The process whose specific outcome is the progression of a neuron that resides in the forebrain, from its initial commitment to its fate, to the fully functional differentiated cell.

The series of molecular signals generated as a consequence of a brain-derived neurotrophic factor receptor binding to one of its physiological ligands.

Any process that activates or increases the frequency, rate or extent of protein binding.

A series of molecular signals initiated by the binding of nerve growth factor (NGF) to a receptor on the surface of the target cell, and ending with regulation of a downstream cellular process, e.g. transcription.

Any process that activates or increases the activity of a GTPase.

Any process that stops, prevents, or reduces the frequency, rate or extent of the chemical reactions and pathways resulting in the formation of melanin.

A process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a nerve growth factor stimulus.

Any process that activates or increases the frequency, rate or extent of vasculogenesis.

Any process that activates or increases the frequency, rate or extent of neuron migration.

An intracellular protein kinase cascade containing at least a MAPK, a MAPKK and a MAP3K. The cascade can also contain an additional tiers: the upstream MAP4K. The kinases in each tier phosphorylate and activate the kinase in the downstream tier to transmit a signal within a cell.

The formation of a cell surface protrusion, such as a lamellipodium or filopodium, at the leading edge of a migrating cell.

The process during Drosophila embryogenesis whereby the ectodermal cells of the lateral epithelium stretch in a coordinated fashion to internalize the amnioserosa cells and close the embryo dorsally.

The process during Drosophila embryogenesis whereby the ectodermal cells of the lateral epithelium stretch in a coordinated fashion to internalize the amnioserosa cells and close the embryo dorsally.

The process in which the anatomical structures of the imaginal disc-derived wing are generated and organized. The wing is an appendage modified for flying.

The process whose specific outcome is the progression of the male genitalia over time, from formation as part of the genital disc to the mature structure. An example of this is found in Drosophila melanogaster.

The process whose specific outcome is the progression of the epidermis over time, from its formation to the mature structure. The epidermis is the outer epithelial layer of an animal, it may be a single layer that produces an extracellular material (e.g. the cuticle of arthropods) or a complex stratified squamous epithelium, as in the case of many vertebrate species.

Any process that modulates the surface configuration of an embryonic cell.

The periodic shedding of part or all of a collagen and cuticulin-based cuticle, which is then replaced by a new collagen and cuticulin-based cuticle. An example of this is found in the Nematode worm, Caenorhabditis elegans.

Any process by which an organism or tissue maintains a population of germ-line stem cells.

A series of molecular signals within the cell that are mediated by a member of the Rap family of proteins switching to a GTP-bound active state.

The aggregation, arrangement and bonding together of a set of components to form an adherens junction. An adherens junction is a cell junction at which the cytoplasmic face of the plasma membrane is attached to actin filaments.

The directed movement of a hemocyte within the embryo. Hemocytes are blood cells associated with a hemocoel (the cavity containing most of the major organs of the arthropod body) which are involved in defense and clotting of hemolymph, but not involved in transport of oxygen. In Drosophila, embryonic hemocytes originate from the head mesoderm as a cluster of cells. The cluster splits into two and one group of cells crosses the amnioserosa. Both populations then spread toward the middle of the embryo and then disperse evenly throughout the embryo.

Synthesis and deposition of a collagen and cuticulin-based noncellular, hardened, or membranous secretion from an epithelial sheet. An example of this process is found in Caenorhabditis elegans.

Any process that activates or increases the activity of a GTPase.

Any process which activates, maintains or increases the frequency, rate or extent of cAMP-mediated signaling, a series of molecular signals in which a cell uses cyclic AMP to convert an extracellular signal into a response.

Any process that modulates the frequency, rate or extent of compound eye photoreceptor development.

Any process that activates or increases the frequency, rate or extent of protein kinase activity.

The complete process of formation and maturation of an ovum or female gamete from a primordial female germ cell. Examples of this process are found in Mus musculus and Drosophila melanogaster.

The process whose specific outcome is the progression of the compound eye over time, from its formation to the mature structure. The compound eye is an organ of sight that contains multiple repeating units, often arranged hexagonally. Each unit has its own lens and photoreceptor cell(s) and can generate either a single pixelated image or multiple images, per eye.

The establishment of a barrier between endothelial cell layers, such as those in the brain, lung or intestine, to exert specific and selective control over the passage of water and solutes, thus allowing formation and maintenance of compartments that differ in fluid and solute composition.

Any process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a cAMP (cyclic AMP, adenosine 3',5'-cyclophosphate) stimulus.

Any process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a cGMP (cyclic GMP, guanosine 3',5'-cyclophosphate) stimulus.

The series of molecular signals generated as a consequence of an adrenergic receptor binding to its physiological ligand, where the pathway proceeds with activation of adenylyl cyclase and a subsequent increase in the concentration of cyclic AMP (cAMP).

Any process that modulates the frequency, rate or extent of cell junction assembly.

A series of molecular signals that proceeds with an activated receptor promoting the exchange of GDP for GTP on the alpha-subunit of an associated heterotrimeric G-protein complex. The GTP-bound activated alpha-G-protein then dissociates from the beta- and gamma-subunits to further transmit the signal within the cell. The pathway begins with receptor-ligand interaction, or for basal GPCR signaling the pathway begins with the receptor activating its G protein in the absence of an agonist, and ends with regulation of a downstream cellular process, e.g. transcription. The pathway can start from the plasma membrane, Golgi or nuclear membrane (PMID:24568158 and PMID:16902576).

A series of molecular signals that proceeds with an activated receptor promoting the exchange of GDP for GTP on the alpha-subunit of an associated heterotrimeric G-protein complex. The GTP-bound activated alpha-G-protein then dissociates from the beta- and gamma-subunits to further transmit the signal within the cell. The pathway begins with receptor-ligand interaction, or for basal GPCR signaling the pathway begins with the receptor activating its G protein in the absence of an agonist, and ends with regulation of a downstream cellular process, e.g. transcription. The pathway can start from the plasma membrane, Golgi or nuclear membrane (PMID:24568158 and PMID:16902576).

The series of molecular signals generated as a consequence of a peptide neurotransmitter binding to a cell surface receptor.

The series of molecular signals generated as a consequence of a peptide neurotransmitter binding to a cell surface receptor.

Any process that stops, prevents or reduces the rate or extent of cell proliferation.

Any intracellular signal transduction in which the signal is passed on within the cell via cyclic AMP (cAMP). Includes production of cAMP, and downstream effectors that further transmit the signal within the cell.

Any intracellular signal transduction in which the signal is passed on within the cell via cyclic AMP (cAMP). Includes production of cAMP, and downstream effectors that further transmit the signal within the cell.

Formation of a microvillus, a thin cylindrical membrane-covered projection on the surface of a cell.

The process whose specific outcome is the progression of a neuron projection over time, from its formation to the mature structure. A neuron projection is any process extending from a neural cell, such as axons or dendrites (collectively called neurites).

Any process that activates or increases the frequency, rate or extent of protein kinase activity.

A process that modulates synaptic plasticity, the ability of synapses to change as circumstances require. They may alter function, such as increasing or decreasing their sensitivity, or they may increase or decrease in actual numbers.

Any process that stops, prevents, or reduces the frequency, rate or extent of dendrite morphogenesis.

Any process that activates or increases the frequency, rate or extent of signal transduction mediated by the ERK1 and ERK2 cascade.

Any process that activates or increases the frequency, rate or extent of signal transduction mediated by the ERK1 and ERK2 cascade.

Any process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a cAMP (cyclic AMP, adenosine 3',5'-cyclophosphate) stimulus.

A process in which a protein is transported to, or maintained in, a specific location in the plasma membrane.

Any process that activates or increases the frequency, rate or extent of cAMP-dependent protein kinase activity.

Any process that activates or increases the frequency, rate or extent of dendritic cell apoptotic process.

An intracellular protein kinase cascade containing at least a MAPK, a MAPKK and a MAP3K. The cascade can also contain an additional tiers: the upstream MAP4K. The kinases in each tier phosphorylate and activate the kinase in the downstream tier to transmit a signal within a cell.

An intracellular protein kinase cascade containing at least a MAPK, a MAPKK and a MAP3K. The cascade can also contain an additional tiers: the upstream MAP4K. The kinases in each tier phosphorylate and activate the kinase in the downstream tier to transmit a signal within a cell.

Any series of molecular signals in which a small monomeric GTPase relays one or more of the signals.

Any process that stops, prevents or reduces the rate or extent of cell proliferation.

Any intracellular signal transduction in which the signal is passed on within the cell via cyclic AMP (cAMP). Includes production of cAMP, and downstream effectors that further transmit the signal within the cell.

The process whose specific outcome is the progression of a neuron projection over time, from its formation to the mature structure. A neuron projection is any process extending from a neural cell, such as axons or dendrites (collectively called neurites).

A series of molecular signals within the cell that are mediated by a member of the Rap family of proteins switching to a GTP-bound active state.

The process in which a signal is passed on to downstream components within the cell, which become activated themselves to further propagate the signal and finally trigger a change in the function or state of the cell.

Any process which activates, maintains or increases the frequency, rate or extent of cAMP-mediated signaling, a series of molecular signals in which a cell uses cyclic AMP to convert an extracellular signal into a response.

Any process that stops, prevents, or reduces the frequency, rate or extent of dendrite morphogenesis.

The establishment of a barrier between endothelial cell layers, such as those in the brain, lung or intestine, to exert specific and selective control over the passage of water and solutes, thus allowing formation and maintenance of compartments that differ in fluid and solute composition.

Any process that activates or increases the frequency, rate or extent of signal transduction mediated by the ERK1 and ERK2 cascade.

Any process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a cGMP (cyclic GMP, guanosine 3',5'-cyclophosphate) stimulus.

The series of molecular signals generated as a consequence of an adrenergic receptor binding to its physiological ligand, where the pathway proceeds with activation of adenylyl cyclase and a subsequent increase in the concentration of cyclic AMP (cAMP).

The establishment of a barrier between endothelial cell layers of the intestine to exert specific and selective control over the passage of water and solutes, thus allowing formation and maintenance of compartments that differ in fluid and solute composition.

Any process that modulates the frequency, rate or extent of cell junction assembly.

Any process that activates or increases the frequency, rate or extent of cAMP-dependent protein kinase activity.

Any process that activates or increases the frequency, rate or extent of dendritic cell apoptotic process.

The process whose specific outcome is the progression of a blood vessel over time, from its formation to the mature structure. The blood vessel is the vasculature carrying blood.

The characteristic movement of an immature neuron from germinal zones to specific positions where they will reside as they mature.

A series of molecular signals that proceeds with an activated receptor promoting the exchange of GDP for GTP on the alpha-subunit of an associated heterotrimeric G-protein complex. The GTP-bound activated alpha-G-protein then dissociates from the beta- and gamma-subunits to further transmit the signal within the cell. The pathway begins with receptor-ligand interaction, or for basal GPCR signaling the pathway begins with the receptor activating its G protein in the absence of an agonist, and ends with regulation of a downstream cellular process, e.g. transcription. The pathway can start from the plasma membrane, Golgi or nuclear membrane (PMID:24568158 and PMID:16902576).

The series of molecular signals generated as a consequence of a peptide neurotransmitter binding to a cell surface receptor.

A series of molecular signals within the cell that are mediated by a member of the Ras superfamily of proteins switching to a GTP-bound active state.

Any process that stops, prevents or reduces the rate or extent of cell proliferation.

Any process that stops, prevents or reduces the rate or extent of cell proliferation.

Any process that increases the rate, frequency or extent of neuron projection development. Neuron projection development is the process whose specific outcome is the progression of a neuron projection over time, from its formation to the mature structure. A neuron projection is any process extending from a neural cell, such as axons or dendrites (collectively called neurites).

Any process that increases the rate, frequency or extent of neuron projection development. Neuron projection development is the process whose specific outcome is the progression of a neuron projection over time, from its formation to the mature structure. A neuron projection is any process extending from a neural cell, such as axons or dendrites (collectively called neurites).

Any intracellular signal transduction in which the signal is passed on within the cell via cyclic AMP (cAMP). Includes production of cAMP, and downstream effectors that further transmit the signal within the cell.

The process whose specific outcome is the progression of the brain ventricular system over time, from its formation to the mature structure. The brain ventricular system consists of four communicating cavities within the brain that are continuous with the central canal of the spinal cord. These cavities include two lateral ventricles, the third ventricle and the fourth ventricle. Cerebrospinal fluid fills the ventricles and is produced by the choroid plexus.

The process whose specific outcome is the progression of a neuron that resides in the forebrain, from its initial commitment to its fate, to the fully functional differentiated cell.

The process whose specific outcome is the progression of a neuron projection over time, from its formation to the mature structure. A neuron projection is any process extending from a neural cell, such as axons or dendrites (collectively called neurites).

The process whose specific outcome is the progression of a neuron projection over time, from its formation to the mature structure. A neuron projection is any process extending from a neural cell, such as axons or dendrites (collectively called neurites).

The series of molecular signals generated as a consequence of a brain-derived neurotrophic factor receptor binding to one of its physiological ligands.

The series of molecular signals generated as a consequence of a brain-derived neurotrophic factor receptor binding to one of its physiological ligands.

Any process that activates or increases the frequency, rate or extent of protein binding.

A series of molecular signals within the cell that are mediated by a member of the Rap family of proteins switching to a GTP-bound active state.

A series of molecular signals initiated by the binding of nerve growth factor (NGF) to a receptor on the surface of the target cell, and ending with regulation of a downstream cellular process, e.g. transcription.

A series of molecular signals initiated by the binding of nerve growth factor (NGF) to a receptor on the surface of the target cell, and ending with regulation of a downstream cellular process, e.g. transcription.

Any process that modulates the rate of GTP hydrolysis by a GTPase.

Any process which activates, maintains or increases the frequency, rate or extent of cAMP-mediated signaling, a series of molecular signals in which a cell uses cyclic AMP to convert an extracellular signal into a response.

Any process that activates or increases the frequency, rate or extent of protein kinase activity.

Any process that activates or increases the frequency, rate or extent of protein kinase activity.

Any process that stops, prevents, or reduces the frequency, rate or extent of the chemical reactions and pathways resulting in the formation of melanin.

A process that modulates synaptic plasticity, the ability of synapses to change as circumstances require. They may alter function, such as increasing or decreasing their sensitivity, or they may increase or decrease in actual numbers.

A process that modulates synaptic plasticity, the ability of synapses to change as circumstances require. They may alter function, such as increasing or decreasing their sensitivity, or they may increase or decrease in actual numbers.

Any process that stops, prevents, or reduces the frequency, rate or extent of dendrite morphogenesis.

Any process that stops, prevents, or reduces the frequency, rate or extent of dendrite morphogenesis.

The establishment of a barrier between endothelial cell layers, such as those in the brain, lung or intestine, to exert specific and selective control over the passage of water and solutes, thus allowing formation and maintenance of compartments that differ in fluid and solute composition.

Any process that activates or increases the frequency, rate or extent of signal transduction mediated by the ERK1 and ERK2 cascade.

Any process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a cAMP (cyclic AMP, adenosine 3',5'-cyclophosphate) stimulus.

Any process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a cAMP (cyclic AMP, adenosine 3',5'-cyclophosphate) stimulus.

Any process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a cGMP (cyclic GMP, guanosine 3',5'-cyclophosphate) stimulus.

The series of molecular signals generated as a consequence of an adrenergic receptor binding to its physiological ligand, where the pathway proceeds with activation of adenylyl cyclase and a subsequent increase in the concentration of cyclic AMP (cAMP).

The establishment of a barrier between endothelial cell layers of the intestine to exert specific and selective control over the passage of water and solutes, thus allowing formation and maintenance of compartments that differ in fluid and solute composition.

Any process that modulates the frequency, rate or extent of cell junction assembly.

A process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a nerve growth factor stimulus.

A process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a nerve growth factor stimulus.

Any process that activates or increases the frequency, rate or extent of cAMP-dependent protein kinase activity.

Any process that activates or increases the frequency, rate or extent of cAMP-dependent protein kinase activity.

Any process that activates or increases the frequency, rate or extent of dendritic cell apoptotic process.

Any process that activates or increases the frequency, rate or extent of dendritic cell apoptotic process.

Any process that activates or increases the frequency, rate or extent of vasculogenesis.

Any process that activates or increases the frequency, rate or extent of neuron migration.

The part of the cytoplasm that does not contain organelles but which does contain other particulate matter, such as protein complexes.

The membrane surrounding a cell that separates the cell from its external environment. It consists of a phospholipid bilayer and associated proteins.

The region of the plasma membrane located at the apical end of the cell.

A membrane-bounded intracellular vesicle formed by invagination of the plasma membrane around an extracellular substance. Endocytic vesicles fuse with early endosomes to deliver the cargo for further sorting.

A structure comprised of a core structure (in most organisms, a pair of centrioles) and peripheral material from which a microtubule-based structure, such as a spindle apparatus, is organized. Centrosomes occur close to the nucleus during interphase in many eukaryotic cells, though in animal cells it changes continually during the cell-division cycle.

The membrane surrounding a cell that separates the cell from its external environment. It consists of a phospholipid bilayer and associated proteins.

A cell junction that forms a connection between two or more cells in a multicellular organism; excludes direct cytoplasmic junctions such as ring canals.

A stable assembly of two or more macromolecules, i.e. proteins, nucleic acids, carbohydrates or lipids, in which at least one component is a protein and the constituent parts function together.

A prolongation or process extending from a nerve cell, e.g. an axon or dendrite.

The portion of a neuron that includes the nucleus, but excludes cell projections such as axons and dendrites.

The junction between a nerve fiber of one neuron and another neuron, muscle fiber or glial cell. As the nerve fiber approaches the synapse it enlarges into a specialized structure, the presynaptic nerve ending, which contains mitochondria and synaptic vesicles. At the tip of the nerve ending is the presynaptic membrane; facing it, and separated from it by a minute cleft (the synaptic cleft) is a specialized area of membrane on the receiving cell, known as the postsynaptic membrane. In response to the arrival of nerve impulses, the presynaptic nerve ending secretes molecules of neurotransmitters into the synaptic cleft. These diffuse across the cleft and transmit the signal to the postsynaptic membrane.

All of the contents of a cell excluding the plasma membrane and nucleus, but including other subcellular structures.

A prelysosomal endocytic organelle differentiated from early endosomes by lower lumenal pH and different protein composition. Late endosomes are more spherical than early endosomes and are mostly juxtanuclear, being concentrated near the microtubule organizing center.

The part of the cytoplasm that does not contain organelles but which does contain other particulate matter, such as protein complexes.

The apical end of the lateral plasma membrane of epithelial cells.

Cytoplasm situated near, or occurring around, the nucleus.

A collagen and cuticulin-based noncellular, multilayered structure that is synthesized by an underlying ectodermal (hypodermal) cell layer. The cuticle serves essential functions in body morphology, locomotion, and environmental protection. An example of this component is found in Caenorhabditis elegans.

The part of the cytoplasm that does not contain organelles but which does contain other particulate matter, such as protein complexes.

The region of the plasma membrane located at the apical end of the cell.

A membrane-bounded intracellular vesicle formed by invagination of the plasma membrane around an extracellular substance. Endocytic vesicles fuse with early endosomes to deliver the cargo for further sorting.

All of the contents of a cell excluding the plasma membrane and nucleus, but including other subcellular structures.

A prelysosomal endocytic organelle differentiated from early endosomes by lower lumenal pH and different protein composition. Late endosomes are more spherical than early endosomes and are mostly juxtanuclear, being concentrated near the microtubule organizing center.

A structure comprised of a core structure (in most organisms, a pair of centrioles) and peripheral material from which a microtubule-based structure, such as a spindle apparatus, is organized. Centrosomes occur close to the nucleus during interphase in many eukaryotic cells, though in animal cells it changes continually during the cell-division cycle.

The membrane surrounding a cell that separates the cell from its external environment. It consists of a phospholipid bilayer and associated proteins.

The component of the plasma membrane consisting of the gene products and protein complexes having at least some part of their peptide sequence embedded in the hydrophobic region of the membrane.

An occluding cell-cell junction that is composed of a branching network of sealing strands that completely encircles the apical end of each cell in an epithelial sheet; the outer leaflets of the two interacting plasma membranes are seen to be tightly apposed where sealing strands are present. Each sealing strand is composed of a long row of transmembrane adhesion proteins embedded in each of the two interacting plasma membranes.

A lipid bilayer along with all the proteins and protein complexes embedded in it an attached to it.

Cytoplasm situated near, or occurring around, the nucleus.

All of the contents of a cell excluding the plasma membrane and nucleus, but including other subcellular structures.

A prelysosomal endocytic organelle differentiated from early endosomes by lower lumenal pH and different protein composition. Late endosomes are more spherical than early endosomes and are mostly juxtanuclear, being concentrated near the microtubule organizing center.

A cell junction that forms a connection between two or more cells in a multicellular organism; excludes direct cytoplasmic junctions such as ring canals.

An occluding cell-cell junction that is composed of a branching network of sealing strands that completely encircles the apical end of each cell in an epithelial sheet; the outer leaflets of the two interacting plasma membranes are seen to be tightly apposed where sealing strands are present. Each sealing strand is composed of a long row of transmembrane adhesion proteins embedded in each of the two interacting plasma membranes.

A lipid bilayer along with all the proteins and protein complexes embedded in it an attached to it.

A lipid bilayer along with all the proteins and protein complexes embedded in it an attached to it.

A stable assembly of two or more macromolecules, i.e. proteins, nucleic acids, carbohydrates or lipids, in which at least one component is a protein and the constituent parts function together.

A stable assembly of two or more macromolecules, i.e. proteins, nucleic acids, carbohydrates or lipids, in which at least one component is a protein and the constituent parts function together.

A prolongation or process extending from a nerve cell, e.g. an axon or dendrite.

A prolongation or process extending from a nerve cell, e.g. an axon or dendrite.

The portion of a neuron that includes the nucleus, but excludes cell projections such as axons and dendrites.

The portion of a neuron that includes the nucleus, but excludes cell projections such as axons and dendrites.

The junction between a nerve fiber of one neuron and another neuron, muscle fiber or glial cell. As the nerve fiber approaches the synapse it enlarges into a specialized structure, the presynaptic nerve ending, which contains mitochondria and synaptic vesicles. At the tip of the nerve ending is the presynaptic membrane; facing it, and separated from it by a minute cleft (the synaptic cleft) is a specialized area of membrane on the receiving cell, known as the postsynaptic membrane. In response to the arrival of nerve impulses, the presynaptic nerve ending secretes molecules of neurotransmitters into the synaptic cleft. These diffuse across the cleft and transmit the signal to the postsynaptic membrane.

The junction between a nerve fiber of one neuron and another neuron, muscle fiber or glial cell. As the nerve fiber approaches the synapse it enlarges into a specialized structure, the presynaptic nerve ending, which contains mitochondria and synaptic vesicles. At the tip of the nerve ending is the presynaptic membrane; facing it, and separated from it by a minute cleft (the synaptic cleft) is a specialized area of membrane on the receiving cell, known as the postsynaptic membrane. In response to the arrival of nerve impulses, the presynaptic nerve ending secretes molecules of neurotransmitters into the synaptic cleft. These diffuse across the cleft and transmit the signal to the postsynaptic membrane.

Cytoplasm situated near, or occurring around, the nucleus.