An in vitro whole-brain preparation of infrared-sensitive snakes was used to demonstrate the implementation of a topographical map at hierarchical levels of the signaling pathway from the sensory periphery to the first central nucleus in the hindbrain. The organotopic organization of environmental infrared cues is the likely anatomical prerequisite for the observed multimodal integration in the optic tectum.

The central pathways subserving the feline pupillary light reflex were examined by defining retinal input to the olivary pretectal nucleus, its midbrain projections, and the premotor neurons within it. Labeled dendrites (Den*) of olivary neurons receive monosynaptic input (arrowhead) from anterogradely labeled retinal terminals (At*) and project to the anterior portion of the preganglionic motoneuron population. At, axonal terminal.

The preganglionic parasympathetic motoneurons controlling the pupil in the cat differ in distribution, morphology, and ultrastructure from those that control the lens. Fusiform pupillary motoneurons lie rostral to the oculomotor nucleus. Multipolar lens motoneurons lie dorsal and ventral to it. The former receive monosynaptic input (photomicrograph) from the olivary pretectal nucleus.

The authors describe an advanced nonvisual system in Atlantic halibut, prior to the development of functional eyes, with melanopsin-expressing cells in several brain regions and in spinal cord. In the pineal complex, melanopsin-positive cells are found lateral and adjacent to the central rosette of exorhodopsin photoreceptors.

Using freeze-fracture immunogold labeling for AMPA and NMDA receptors at four distinct types of excitatory synapses in cochlear nucleus, authors reveal target- and input-dependent features in the structure, number, and organization of AMPA and NMDA receptors in auditory nerve and parallel fiber synapses.

Lentivirus anterograde tracing study in the rat revealed that the subthalamus receives heavy projections from the motor and sensory cortices, the cortico-subthalamic projections have a large-scale functional organization that encompasses both the subthalamic nucleus (STN) and two subdivisions of the zona incerta (ZIv and ZId), and the group of cortical axons that originate from a particular area of Cx sequentially innervate and form separate terminal fields in the STN, ZIv, and ZId.

The authors show that developing myelinated nerves initially express a variety of sodium channel isoforms at nodes of Ranvier. This nonselective isoform expression is then developmentally eliminated by both neuronal and myelinating Schwann cell mechanisms, resulting in the selective expression of only the Na_v1.6 isoform at nodes of mature nerves.

Throughout subcortical auditory structures, neurons expressing parvalbumin and calbindin change in density with age. In cerebral structures, these neurons are physiological inhibitors. This study demonstrates that in subcortical auditory structures of macaques only fractions of these neurons are GABAergic, so they are not analogous. Furthermore, these proportions show age-related changes.

Using a combination of patch-clamp recordings and morphological measurements, the authors analyze the relationship between aberrant physiological activity and anatomical features of retinal ganglion cells in a mouse model of retinal degeneration. Cluster analysis reveals distinct groupings of cells, which correlate to the type and magnitude of oscillatory input.

Multiple endogenous markers can be used to analyze adult neurogenesis. This figure presents a schematic illustration of the different stages in the life of a neuron born in the adult brain and examples of the characteristic proteins expressed at these stages in the mammalian brain. Due to limitations in available antibodies and their specificity, only a fraction of these markers have been used and to some extent validated to study neurogenesis in the adult avian brain. These markers are highlighted in red in the figure.