Pontine reticulospinal projections in the neonatal mouse: Internal organization and axon trajectories.

Pontine Reticulospinal and Other Bulbospinal Projections in the Newborn Mouse

Organization of pontine reticulospinal inputs to motoneurons controlling axial and limb muscles in the neonatal mouse.

Using optical recording of synaptically mediated calcium transients and selective spinal lesions, we investigated the pattern of activation of spinal motoneurons (MNs) by the pontine reticulospinal projection in isolated brain stem-spinal cord preparations from the neonatal mouse. Stimulation sites throughout the region where the pontine reticulospinal neurons reside reliably activated MNs at c...

Reticulospinal systems mediate atonia with short and long latencies.

The pontomedullary region is responsible for both the tonic and phasic reduction of muscle activity in rapid-eye-movement sleep and contributes to the control of muscle tone in waking. This study focused on determining the time course of activity in the pontomedullary systems mediating atonia. Short-train stimulations (3 0.2-ms pulses at 330 Hz) of the pons and medulla suppressed neck and hindl...

Activity-Dependent Callosal Axon Projections in Neonatal Mouse Cerebral Cortex

Callosal axon projections are among the major long-range axonal projections in the mammalian brain. They are formed during the prenatal and early postnatal periods in the mouse, and their development relies on both activity-independent and -dependent mechanisms. In this paper, we review recent findings about the roles of neuronal activity in callosal axon projections. In addition to the well-do...

Organization of functional synaptic connections between medullary reticulospinal neurons and lumbar descending commissural interneurons in the neonatal mouse.

The medullary reticular formation (MRF) of the neonatal mouse is organized so that the medial and lateral MRF activate hindlimb and trunk motoneurons (MNs) with differential predominance. The goal of the present study was to investigate whether this activation is polysynaptic and mediated by commissural interneurons with descending axons (dCINs) in the lumbar spinal cord. To this end, we tested...