Inhibitory transmission of histamine in insects antennal lobe- A review

Abstract

Antennal lobe is an insects’ analogue to specific spatio – temporal activity patterns of the olfactory bulb of vertebrates, where the first synaptic processing of the olfactory input from the antennae occurs. It is involved in the processing of odours to shape afferent odour response. Fundamental components of the olfactory network in the antennal lobe include the local interneurons (LI) and the projection (output) neurons. Majority of LI in most insects are non-gamma – Amino butyric acid (GABA), histamine been one of the possible candidates. This is because, histamine - like immunoreactivity is found in a number of interneurons in the central nervous system of various insects and, this uneven distribution of histamine in the brain suggests that it is a neuro transmitter. A brief description on the chemical composition of histamine, its formation and precursors, physiology, neurophysiology and presumed transmission were carefully enunciated. The review underscores the significance of inhibitory transmission of histamine in the insect antennal lobe.