Figure 7.

Proposed model of socially mediated shift in synaptic reconfiguration underlies synergistic modulation of the motor circuits. A, Dominants proposed model: the relatively higher Drd1b expression in glycinergic neurons strengthens the dopaminergic→glycinergic synapse, promoting glycine release, and inhibition of the M-cell. The disproportionately stronger dopaminergic→glycinergic pathway compared with the weak GABAergic→glycinergic input culminates in the activation of the glycinergic neurons and lower excitability of the M-cell. Lower panel, Blockage of either Drd1b or GlyR facilities behavioral switch from swimming to escape. B, Subordinates proposed model: the disproportionately weaker dopaminergic→glycinergic pathway because of decreased Drd1b expression in the glycinergic neurons culminates in the reduced activity of the glycinergic neurons and enhanced excitability of the M-cell. Lower panel, Blockage of either Drd1b or GlyR has no effect on escape or swimming activity. However, blockage of GABAergic input promotes dominant like locomotor behavior that promotes swimming over escape. Proposed strong pathways are illustrated as solid colors, while weak pathways are illustrated as faded colors. (+) denotes excitatory synapse, (−) denotes inhibitory synapse.