Connections of Vomeronasal (and Main-Olfactory) Systems
The specialist vomeronasal sensory neurons are located in the sensory epithelium of the VNO. High sensitivity and selectivity for chemical-signal stimuli is endowed by receptor proteins on their surface. Neurons in rostral AOB receive input from the apically located VNO sensory neurons (with V1R proteins). Caudal AOB neurons receive information from (deep, V2R) sensory neurons. AOB circuits analyze the chemical composition of the stimulus and neurons in both regions carry information centrally to the amygdala. The anterior medial amygdala neurons receive AOB input, sort the information and respond differently than AOB. The posterior medial amygdala appears to respond only to socially relevant stimuli. Appropriate stimuli activate output to the medial preoptic/Hypothalamic areas where behavior is initiated. The generalist main olfactory epithelium (MOE) contains olfactory sensory neurons each expressing one of ~ several hundreds of olfactory receptor (OR) genes and collectively capable of responding to any odor chemical. The MOB neurons receive input from olfactory sensory neurons and send their axons to the olfactory cortex for analysis of odor quality and intensity. Main olfactory information can also reach the "vomeronasal (medial) amygdala" and interact with VNO input. See "Molecular Receptors" "VNO Sensitivity", "Specialist versus Generalist Functions" or "Information pathway to the brain" for more information, or select from a list of Brief Topics or Extended text.