The mammalian olfactory system controls a plethora of functions such as homeostasis, emotions such as fear, anger, pleasure and anxiety, sexual and maternal functions as well as communal behaviours such as distinguishing between tribe or family and outsiders (Lledo et al, 2005).
Rodents have a separate organ known as the vomeronasal organ to detect chemical compounds such as …show more content…
This now begs the question: Can plasticity in the rodent olfactory system be driven by odor-dependent structural and physiological changes?
Plasticity in the Rodent Olfactory System
The olfactory system is innervated by a surfeit of modulatory systems and a profound capability for information storage. This enables its circuitry to display both short and long term synaptic plasticity, experience-dependent neurogenesis and morphological changes in dendrites throughout development.
Short Term Plasticity
Short term plasticity has been noted to occur in the OB, which may be crucial for adaptation and sustainability towards repeated and extended durations as well as perhaps for calibration of sensory systems to cope with various situations such as erratic odours.
For example, when a short stimulus was presented to the OB, both spatial and temporal local patterns of OB circuitry were altered, suggesting a change in strength of synaptic transmission (Spors and Grinvald, 2002). The axon terminals of OR express D2 receptors (D2Rs) and neighbouring juxtaglomerular neurons express dopamine. When the D2Rs are activated in the OB, transmitter release from the OR axons are attenuated, thus decreasing afferent input gain (Reviewed from Wilson et al, …show more content…
Consistently, another investigation (Gutièrrez-Mecinas et al, 2005) which elucidated D2 anatomical distributions in the olfactory glomeruli found it agreeable that D2 receptors act pre-synaptically to regulate glutamate release from the olfactory onto the dendrites M/T cells and PG cells, regulate the glutamatergic synapses of these dendrites and control the strength of neurotransmission from GABAergic and dopaminergic PG cells onto M/T