Neurotransmitters cause a response in the postsynaptic neuron by​

Stimulation of excitatory receptors by neurotransmitter binding causes depolarization of the postsynaptic plasma membrane, promoting generation of an action potential. Conversely, stimulation of inhibitory receptors causes hyperpolarization of the postsynaptic membrane, repressing generation of an action potential.

and after water is usually warmed by the sun the water temperature raises and then evaporates .