Integration of olfactory and auditory cues eliciting parental behavior.

Parental care is crucial for the survival of all mammalian species. Given the evolutionary importance of parenting, this behavioral repertoire must be supported by circuitry that is innate but also capable of learning and flexibility - adjusting to changing environmental demands. In rodents, parental care is triggered by the perception of cues emitted by a pup. Caregiver-pup interactions are often composed of multimodal sensory stimuli that require caregivers to integrate across sensory modalities. In this review, we focus on two sensory modalities essential for the parental experience: smell and hearing. We examine how smell and hearing are combined with other senses to identify offspring in need of care. Understanding how multimodal stimuli are integrated in the caregiver brain to inform parental behavior is an important step in understanding the circuitry that underlies this complex and crucial behavioral repertoire. In this review, we will discuss recent advances in the field of rodent parental behavior, highlighting studies that have begun to disentangle the neural circuitry that processes the multisensory cues that are involved in caregiver-offspring interactions.

Sensory regulation of absence seizures in a mouse model of Gnb1 encephalopathy.

Absence seizures, manifested by spike-wave discharges (SWD) in the electroencephalogram, display synchronous reciprocal excitation between the neocortex and thalamus. Recent studies have revealed that inhibitory neurons in the reticular thalamic (RT) nucleus and excitatory thalamocortical (TC) neurons are two subcortical players in generating SWD. However, the signals that drive SWD-related activity remain elusive. Here, we show that SWD predominately occurs during wakefulness in several mouse models of absence epilepsy. In more focused studies of Gnb1 mutant mice, we found that sensory input regulates SWD. Using in vivo recording, we demonstrate that TC cells are activated prior to the onset of SWD and then inhibited during SWD. On the contrary, RT cells are slightly inhibited prior to SWD, but are strongly activated during SWD. Furthermore, chemogenetic activation of TC cells leads to the enhancement of SWD. Together, our results indicate that sensory input can regulate SWD by activating the thalamocortical pathway.