Paternal Deprivation Alters Region- and Age-Specific Interneuron Expression Patterns in the Biparental Rodent, Octodon degus

The impact of paternal care on the postnatal development of inhibitory neuronal subpopulations in prefrontal and limbic brain regions was studied in the rodent Octodon degus. Comparing offspring from biparental families with animals raised by a single mother revealed region-specific deprivation-induced changes in the density of PARV- and CaBP-D28k expressing cells. Some deprivation-induced changes were only seen at P21: elevated CaBP-D28k-positive neurons in the orbitofrontal cortex, CA1, CA3, and dentate gyrus (DG) and elevated PARV-positive neurons in the lateral orbitofrontal, prelimbic/infralimbic (PL/IL), DG and CA1, nucleus accumbens, and amygdala. Some deprivation-induced changes were obvious in both age groups: increased CaBP-D28k-positive neurons in the nucleus accumbens shell and increased PARV-positive neurons in the ventral orbitofrontal. Some deprivation-induced changes were only seen in adulthood: increased CaBP-D28k-positive neurons in the amygdala and decreased PARV-positive neurons in the PL/IL and in CA3. In CA1, PARV-positive neurons were increased at P21 and decreased in adulthood. The functional significance of the deprivation-induced changes in PARV-positive neurons, which are involved in gamma oscillations and thereby affect information processing and which appear to be key players for critical period plasticity in sensory cortex development, as well as the behavioral implications remain to be further elucidated.