Oligodendrocyte precursor cells (OPCs) originate in multiple restricted regions of the developing central nervous system (CNS). Here, we focus on morphological changes of oligodendrocyte lineage cells and their cellular dynamics including cell motility and proliferation. Morphological studies with molecular markers for OPCs suggest distinct spatiotemporal patterns of OPC migration in vivo, which are directly demonstrated by application of exogenous fluorescent markers to OPCs. Extensive proliferation of OPCs in the CNS parenchyma is also demonstrated by pulse labeling of the cells with bromodeoxyuridine. The results strongly suggest that oligodendrocyte lineage cells are highly motile and actively proliferate with an elongated morphology. These data provide insights into the potential molecular mechanisms of OPC dispersal throughout the CNS.

We report here on the amplectic behavior of the Japanese treefrog (Hyla japonica) in microgravity. Treefrogs were exposed to 35 cycles of altered gravity, including ≈ 1.5 sec of G < 0.1 every 3 min and 15 sec, on the FreeFall “G.0” ride at Space World amusement park in Kitakyushu, Japan. During this period a pair of frogs spontaneously entered and maintained amplexus for 1 hr 20 min, before being removed from the ride. In freefall, the pair extended their hindlimbs in the characteristic posture of treefrogs in microgravity. This is the first report of a vertebrate entering and sustaining a copulatory or amplectic posture under gravitational extremes, including true freefall. These observations bode well for the potential of anurans to breed in microgravity and to be used for biological research in space.

Astrocytes, once regarded primarily as structural and metabolic support cells, are now increasingly recognized as active participants in neural information processing. Within respiratory control networks, astrocytes are widely distributed throughout the brainstem and spinal cord, where they engage in bidirectional communication with neurons to regulate breathing. This review summarizes current knowledge regarding the roles of astrocytes in respiratory rhythm and pattern generation, central respiratory chemoreception, hypoxic ventilatory responses, respiratory plasticity, and respiratory pathophysiology. Recent advancements in calcium imaging, optogenetics, and pharmacology have revealed that astrocytes modulate respiratory network activity through intracellular Ca²⁺ signaling and the release of gliotransmitters, particularly ATP. In the ventrolateral medulla and the parafacial respiratory group/retrotrapezoid nucleus, astrocytes contribute to central CO₂/H⁺ chemoreception through mechanisms involving connexin hemichannels, potassium channels, and purinergic signaling. Emerging evidence further suggests that astrocytes participate in central hypoxic responses and adaptive respiratory plasticity. In addition, astrocytic dysfunction has been implicated in several disorders affecting respiratory control, including brainstem astrocytoma, Rett syndrome, sudden infant death syndrome, and sudden unexpected death in epilepsy. Collectively, accumulating evidence identifies astrocytes as integral components of respiratory control networks that contribute to both the maintenance of respiratory homeostasis and the pathogenesis of respiratory dysfunction. A deeper understanding of astrocyte–neuron interactions may provide novel therapeutic opportunities for the treatment of respiratory disorders.