Neurotransmitter Release from Neuronal Dendrites

Where are classical neurotransmitters stored?

small synaptic vesicles (SSVs) in synaptic terminals

What receptors do classical neurotransmitters use?

ionotropic receptors

What receptors do neuropeptides use?

mostly G-protein-coupled

Where are neuropeptides stored?

large dense cored vesicles (LDCVs) - mostly in dendrites, few in synapses

What are the two mechanisms for LDCV secretion?

activity dependent: AP causes Ca²⁺ entry

store-regulated: triggered by agonists inducing intracellular Ca²⁺ release

What is thapsigargin?

calcium mobiliser, selective for ER stores

How is dendritic release triggered?

increases in intracellular calcium through mobilisation of primed stores

How do oxytocin and vasopressin have neurohormonal effects?

diffuse through brain to areas with receptors (even if they don’t have projections)