AP PSYCHOLOGY

Detailed explanation-1: -Acetylcholine (ACh) is an excitatory neurotransmitter secreted by motor neurons that innervate muscle cells, basal ganglia, preganglionic neurons of the autonomic nervous system, and postganglionic neurons of the parasympathetic and sympathetic nervous systems.

Detailed explanation-2: -Synaptic Protein and Receptors Function. Synaptic proteins have two main functions: regulation of neurotransmitter release and participation in the early development of neurons. In regulating the release of neurotransmitters, synaptic proteins can maintain the stability of the synaptic vesicle reservoir.

Detailed explanation-3: -Quantal release of neurotransmitter occurs by fusion of transmitter-filled vesicles in response to calcium influx into the neuron. After exocytosis, vesicles are recycled by endocytosis and subsequently reloaded with neurotransmitter.

Detailed explanation-4: -Two factors are essential for the release of the neurotransmitter from the presynaptic terminal: (1) depolarization of the terminal and (2) the presence of calcium ions (Ca2+) in the extracellular fluid.

Detailed explanation-5: -Neurotransmitters are released from synaptic vesicles in presynaptic neurons in response to neural activity, diffuse across the synaptic cleft, and bind specific receptors in order to bring about changes in postsynaptic neurons.