Question

_______ diffuse across the synaptic cleft and interact with specialized receptor molecules of the receptive membranes of the next neurons in the circuit.

○ lonotropic receptors
○ g - proteins
● neurotransmitters
○ all - or - none responses

Explanation:

Neurotransmitters are chemical messengers that travel across the synaptic cleft to communicate with the next neuron in a neural - circuit by binding to receptors on the receptive membranes. Ionotropic receptors are the type of receptors neurotransmitters can bind to, G - proteins are involved in signal transduction after receptor activation, and all - or - none responses refer to the nature of action potentials in neurons, not the substances that cross the synaptic cleft.

Answer:

C. Neurotransmitters