There are four types of neuromodulatory systems which are termed after the neurotransmitter active within the system. The neurons of each system establish connections with thousands of other neurons.
These numerous diverse connections allow for modulation of other neural functions. This modulation is not responsible for the direct function, but instead, alters either the cellular or synaptic properties of certain neurons so that neurotransmission between them is changed.
Although the connections are diverse and there are overlapping functions, each modulator system has characteristic general functions.
Use the drop-down menus to select the general function associated with each modulatory pathway.