Biology subjects

Haimson, B.

Publications and source records attributed to Haimson, B..

3 recordsLinked to original sources

bioRxiv2025

Prolactin Shapes Cortical Plasticity in Fathers

Caregiving alters the mammalian brain to support infant survival. While hypothalamic circuits are known to drive innate parental behaviors, information about the effect of parenthood on sensory processing and perception remain scarce, especially in fathers. We longitudinally imaged the same neurons in male mouse primary auditory cortex (ACx) before, during, and after fatherhood using two-photon calcium imaging. Behaviorally, males shifted from pup-directed aggression and self-oriented behaviors to transient parental care. In ACx, fathers showed enhanced and faster discrimination of pup ultrasonic vocalizations compared with matched narrowband noise. Slice electrophysiology revealed increased intrinsic excitability accompanies fatherhood. Mechanistically, we found elevated prolactin signaling in ACx, and manipulating prolactin levels modified the improvement in neuronal discriminability. Together, these results identify-in males-cortical plasticity and link prolactin to experience-dependent plasticity of sensory circuits that support caregiving. Our findings outline a father-specific mechanism that differs in key aspects from similar mechanisms in mothers.

neuroscience↗

bioRxiv2021

Natural loss of function of ephrin-B3 shapes spinal flight circuitry in birds

Flight in birds evolved through patterning of the wings from forelimbs and transition from alternating gait to synchronous flapping. In mammals, the spinal midline guidance molecule ephrin-B3 instructs the wiring that enables limb alternation, and its deletion leads to synchronous hopping gait. Here we show that the ephrin-B3 protein in birds lacks several motifs present in other vertebrates, diminishing its affinity for the EphA4 receptor. The avian ephrin-B3 gene lacks an enhancer that drives midline expression, and is missing in Galliformes. The morphology and wiring at brachial levels of the chick spinal cord resemble those of ephrin-B3 null mice. Importantly, dorsal midline decussation, evident in the mutant mouse, is apparent at the chick brachial level, and is prevented by expression of exogenous ephrin-B3 at the roof plate. Our findings support a role for loss of ephrin-B3 function in shaping the avian brachial spinal cord circuitry and facilitating synchronous wing flapping. TeaserWalking vs flying: Deciphering the organization and evolution of the neuronal network that controls wing flapping in birds.

neuroscience↗

bioRxiv2020

A subpopulation of spinocerebellar tract neurons regulates the stability of bipedal stepping

Peripheral and intraspinal feedback is required to shape and update the output of spinal networks that execute motor behavior. We report that lumbar dI2 spinal interneurons of the chick receive synaptic input from afferents and pre-motoneurons. They innervate contralateral premotor networks in the lumbar and brachial spinal cord and their ascending projections innervate the cerebellum. These findings suggest that dI2 neurons function as interneurons in local lumbar circuits and involved in lumbo-brachial coupling and that part of them deliver peripheral and intraspinal feedback to the cerebellum. Silencing of dI2 neurons leads to destabilized stepping in P8 hatchlings with occasional collapses, variable step-profiles and wide-base walking, suggesting that the dI2 neurons may contribute to stabilization of the bipedal gait.

neuroscience↗