Cerebrospinal Fluid-Contacting Neurons Sense pH Changes and Motion in the Hypothalamus.

CSF-contacting (CSF-c) cells are present in the walls of the brain ventricles and the central canal of the spinal cord and found throughout the vertebrate phylum. We recently identified ciliated somatostatin-/GABA-expressing CSF-c neurons in the lamprey spinal cord that act as pH sensors as well as mechanoreceptors. In the same neuron, acidic and alkaline responses are mediated through ASIC3-like and PKD2L1 channels, respectively.

The Lamprey Pallium Provides a Blueprint of the Mammalian Layered Cortex.

The basic architecture of the mammalian neocortex is remarkably similar across species. Pallial structures in the reptilian brain are considered amniote precursors of mammalian neocortex, whereas pallia of anamniotes ("lower" vertebrates) have been deemed largely insignificant with respect to homology. Here, we examine the cytoarchitecture of the lateral pallium in the lamprey, the phylogenetically oldest group of extant vertebrates.

The Spinal Cord Has an Intrinsic System for the Control of pH.

For survival of the organism, acid-base homeostasis is vital [1, 2]. The respiratory and renal systems are central to this control. Here we describe a novel mechanism, intrinsic to the spinal cord, with sensors that detect pH changes and act to restore pH to physiological levels by reducing motor activity.

Ciliated neurons lining the central canal sense both fluid movement and pH through ASIC3.

Cerebrospinal fluid-contacting (CSF-c) cells are found in all vertebrates but their function has remained elusive. We recently identified one type of laterally projecting CSF-c cell in lamprey spinal cord with neuronal properties that expresses GABA and somatostatin. We show here that these CSF-c neurons respond to both mechanical stimulation and to lowered pH.

The lamprey blueprint of the mammalian nervous system.

The basic features of the vertebrate nervous system are conserved throughout vertebrate phylogeny to a much higher degree than previously thought. In this mini-review, we show that not only the organization of the different motor programs underlying eye, orienting, locomotor, and respiratory movements are similarly organized, but also that the basic structure of the forebrain engaged in the control of movement is conserved. In the lamprey, which diverged already 560 million years ago from the vertebrate line of evolution leading up to primates, the basic components of the basal ganglia are similar to those of mammals in considerable detail.