CB1 KNOCK-OUT MICE PRESENT CHANGES IN NEURONAL CYTOARCHITECTURE WHICH CORRELATE WITH BEHAVIOR ALTERATIONS

VACOTTO, MARINA; SORIANO, DELIA; CALTANA, LAURA ROMINA; BRUSCO, ALICIA

Congreso; 6TH INTERNATIONAL DRUG ABUSE RESEARCH SOCIETY MEETING; 2017

Cannabinoid receptor type 1 (CB1R) is widely distributed in the central nervous system andis involved in processes such as memory, learning, anxiety and mood. Genetic deletion ofCB1R causes behavioral alterations similar to those described in animal models of depressionbut the morphological substrate of this behavior is not fully known. The aim of this work is toanalyze cytoskeletal organization in axons and dendrites, ultrastructural synaptic contact andthe serotonergic system in CB1R knock-out mice (CB1R-/-). CB1R-/-mice showed a decreasein the expression of neuronal cytoskeleton components (Nf-160kDa, Nf-200kDa and MAP-2)and a reduction in the number of primary projections. In addition, results showed a decreasein Synaptophysin expression and an increasing tendency in the number of vesicles in thesynaptic terminal in CB1R-/-mice. The number of synapses was not affected but thepostsynaptic density thickness was reduced. Tryptophan hydroxylase was increased in thedorsal raphe nucleus, without changes in serotonin expression. Serotonin receptor type 1aexpression was increased in CA1 hippocampal area. The absence of CB1R alters neuroalarchitecture affecting synaptic plasticity and modeling. Such changes might correlate withreported changes in the behavior of CB1R-/-mice.