The transcription factor Ebf2 is a marker for somatosensory, motivation and reward systems of the mouse brain.

The functions of the brain arise from the connections between neurons and the formation of neural circuits. Pain and its processing, proprioception, and motivated behaviors are some examples of the result of the activity of these circuits. It is relevant to understand the molecular mechanisms leading to the formation of neural circuits; to identify potential modulators that serve as a foundation for therapeutic approaches for pain management and motivated behavior disorders such as addiction, obesity, and eating disorders. Therefore, it is fundamental to find markers that can track specific neural circuits. In this work, we show that the transcription factor Early B-Cell Factor 2 (Ebf2) is a marker of circuits responsible for somatosensory processing, and motivation and reward systems of the brain. By using genetically engineered 129SvEbf2/Tau-GFP mice, which express the reporter gene green fluorescent protein fused to Tau protein (TGFP) under the control of the Ebf2 gene promoter, we detect the expression of Ebf2 in the mouse brain at different stages of development, from late embryonic stage (E14.5) to adult mice (P56) (n=25 individual brains). At all these stages, we observe expression of Ebf2-TGFP in various components of the somatosensory system including, the substantia gelatinosa (SG) of the spinal cord and the central nervous system: the ventral posteromedial nucleus of the thalamus (VPM), the principal trigeminal (PrV) nucleus and the trigeminal lemniscus, and the parabrachial nucleus (PBN) of the pons. The latter has a role in pain and somatosensory processing but, additionally, it participates in the regulation of motivated behaviors. Related to this motivation system of the brain, we also observe Ebf2-TGFP signals in components of the Dorsal Diencephalic Conduction System; such as the bed nucleus of the stria terminalis (BNST), the stria medullaris (sm), the dorsomedial habenula (dMHb), and the interpeduncular nucleus (IPN) of the midbrain. Ebf2-TGFP axons also connect the IPN to the dorsal tegmental nucleus (DTg). Moreover, we can detect Ebf2-TGFP axons arising from the periaqueductal gray matter (PAG) and innervating the ventral forebrain. Another set of Ebf2 axons originate from the lateral hypothalamic area (LHA); and connects it to the amygdala, which suggests these populations have a role in regulating motivation and reward.