Nicotinic receptors regulate the survival of newborn neurons in the adult olfactory bulb

AUTOR(ES)
FONTE

National Academy of Sciences

RESUMO

Cholinergic axons and nicotinic receptors are abundant in all layers of the olfactory bulb (OB), the main region of newborn neuron integration in the adult brain. Here, we report that the OB granule cell layer in mice lacking the predominant form of brain high-affinity nicotinic acetylcholine receptors (β2-/- mice) displayed nearly 50% more newborn neurons and significantly fewer apoptotic cells than did β2+/+ mice. Conversely, in vivo chronic nicotine exposure significantly decreased the number of newborn granule cells in β2+/+ but not β2-/- adult mice, confirming that the survival of newborn neurons can be controlled by the activation of β2-containing nicotinic acetylcholine receptors. Unexpectedly, investigating the behavioral consequence of an increased number of granule cells in β2-/- mice revealed that these animals have a less robust short-term olfactory memory than their wild-type counterparts. Taken together, these results provide evidence that high-affinity nicotinic receptors are involved in the maturation of adult OB local circuits. They also indicate that an increase in the number of granule cells does not necessarily correlate with better olfactory performance and further highlight the importance of cholinergic afferents for olfactory processing.

ACESSO AO ARTIGO

Documentos Relacionados