Meeting Abstract
Ability to detect and identify odorants in the environment is crucial for survival and reproductive success. For species that breed seasonally or live in dominance hierarchies, plasticity in olfactory abilities associated with changes in internal physiological state has important consequences. However, whether olfactory processing in higher-order decision centers is influenced by an animal’s physiological condition is unknown. We used in vivo single-unit and local field potential (LFP) recordings from a forebrain decision center (ventral telencephalon) in dominant and subordinate male cichlid fish to test the hypothesis that response properties of olfactory neurons differ with male social status. Dominant sexually-active males responded better to sex- and food-related odorants. In contrast, subordinate reproductively-suppressed males responded better to complex odorants from behaving dominant males, suggesting that olfactory signals from rivals may mediate social suppression and allow subordinates to identify opportunities to rise in rank. Odorant-evoked LFP spectral densities were also 2-3-fold greater in dominant males, demonstrating status-dependent differences in processing possibly linking olfactory and other neural inputs to goal-directed behaviors. Thus, high and low ranking males showed distinct odorant-evoked responses reflected by differences in both synaptic inputs (LFPs) and outputs (spikes), which match the behavioral needs of their status-specific lifestyles. For the first time we reveal social and reproductive-state plasticity in olfactory processing neurons of a vertebrate forebrain decision center. This neural plasticity revealed in the cichlid raises the possibility of similar mechanisms in other taxa to facilitate olfactory-mediated behaviors suited to an animal’s current lifestyle.
