Which term refers to a chemical released into a synapse to activate another neuron?

The term that refers to a chemical released into a synapse to activate another neuron is neurotransmitter. Neurotransmitters are essential for communication between neurons, as they are released from the presynaptic neuron into the synaptic cleft and bind to specific receptors on the postsynaptic neuron. This binding can initiate various responses in the receiving neuron, such as exciting or inhibiting its action potentials.

Neurotransmitters play a crucial role in a wide range of processes, including mood regulation, pain perception, and learning and memory. They can have different effects depending on the type of receptor they bind to, highlighting their significance in neural communication.

In contrast, hormones are chemicals that are released into the bloodstream and have effects on distant organs, while synaptic vesicles are small membrane-bound structures that store neurotransmitters before they are released. Receptors, on the other hand, are proteins located on the surface of neurons that bind to neurotransmitters but do not themselves refer to the chemicals that are released. Thus, the focus on neurotransmitters highlights their specific role in neuronal communication.