[1][2][3][4] Through them, the higher cerebral cortex areas can control the immune system, and the body’s homeostatic and stress physiology.
[8][9] These cerebral areas also control smooth muscle and glandular physiological processes through the sympathetic and parasympathetic nervous system including blood circulation, urogenital, gastrointestinal[10] functions, pancreatic gut secretions,[11] respiration, coughing, vomiting, piloerection, pupil dilation, lacrimation and salivation.
[4] The cerebral cortex in rodents shows lateral specialization in its regulation of immunity with immunosuppression being controlled by the right hemisphere, and immunopotention by the left one.
[16] The higher brain top down control of physiology is mediated by the sympathetic and parasympathetic nervous systems in the brainstem,[1][2][3][4] and the hypothalamus.
In this conditioning, a neutral stimulus saccharin is paired in a drink with an agent, cyclophosphamide, that produces an unconditioned response (immunosuppression).