Question

Neurotransmitters are not made in endocrine glands but are not distributed to neurons via CSF not via gap junctions because they do, however:

1) They are synthesized in the presynaptic neuron and released into the synaptic cleft
2) They bind to receptors on the postsynaptic neuron and initiate a response
3) They can be reabsorbed by the presynaptic neuron or broken down by enzymes
4) They play a crucial role in communication between neurons

Answer 1

Neurotransmitters are synthesized in a presynaptic neuron, released into the synaptic gap, and bind to receptors on the postsynaptic neuron to initiate a response. They differ from hormones, which are produced by endocrine glands and distributed through the bloodstream.

Step-by-step explanation:

Neurotransmitters are chemical messengers that are pivotal to the nervous system's function, transmitting signals across a synaptic cleft from one neuron to another. These substances are different from hormones, which are produced by endocrine glands and distributed through the bloodstream. Neurotransmitters are synthesized in the presynaptic neuron and, following an action potential, are released into the synaptic gap. They then bind to receptors on the postsynaptic cell to initiate a specific response, be it excitatory or inhibitory. Moreover, neurotransmitters can be taken back up by the presynaptic neuron or degraded by various enzymes, ensuring the swift termination of the signal and readying the synapse for another round of neurotransmission.

Cerebrospinal fluid (CSF) does not distribute neurotransmitters; rather, they are released directly at synapse sites. This contrasts with hormones, which can travel long distances through the blood to reach various parts of the body. For example, substances like epinephrine can act as a hormone when released into the bloodstream by the adrenal glands, or as a neurotransmitter when released by neurons in the nervous system.