Internal states that animals experience while they are thirsty, hungry, sleepy or aggressive have been found to be linked with the combined activity of various neuromodulators and neurotransmitters. These chemical messengers can drastically change the excitability and functional connectivity of neurons, which in turn plays a role in shaping the animals' behavior.

from Medical Xpress - latest medical and health news stories https://ift.tt/LugRGrC