ANAT 322 Lecture Notes - Lecture 4: Apelin, Corticotropin-Releasing Hormone, Periventricular Nucleus
Document Summary
Morphological plasticity in magnocellular nuclei during dehydration or lactation. When unstimulated, not too many dendrites make contact with the cell body. When stimulated, cell bodies touch each other, along with more synaptic contacts: membrane apposition, dendritic bundling. Glial plasticity is the basis of morphological reorganization in the magnocellular system. Under basal conditions of hormone release, astroglial processes separate magnocellular somata: they fill the voids between neurons. During lactation or dehydration, the astrocytic processes withdraw, thus allowing for direct apposition of somatic and dendritic membranes of neighbouring magnocellular neurons: system is so plastic that it can regulate its own activity using glial cells. Dendritic release of secretory granules in the pvn and son. You get release of ot from the cell body and dendrites. Autoregulation: the neurons also express receptors for the hormone: could lead to auto-excitation or auto-inhibition, depending on the signaling cascade. *need to remember that these neurons express other transmitters.