Distributions of Cells and Neurons across the Cortical Sheet in Old World Macaques
According to previous research, cell and neuron densities vary across neocortex in a similar manner across primate taxa. Here, we provide a more extensive examination of this effect in macaque monkeys. We separated neocortex from the underlying white matter in 4 macaque monkey hemispheres (1 Macaca nemestrina, 2 Macaca radiata,and 1Macaca mulatta), manually flattened the neocortex, and divided it into smaller tissue pieces for analysis. The number of cells and neurons were determined for each piece across the cortical sheet using flow cytometry. Primary visual cortex had the most densely packed neurons and primary motor co...
Source: Brain, Behavior and Evolution - August 22, 2016 Category: Neurology Source Type: research
Mechanosensory Lateral Line Nerve Projections to Auditory Neurons in the Dorsal Descending Octaval Nucleus in the Goldfish, < b > < i > Carassius auratus < /i > < /b >
This report definitively demonstrates that mechanosensory LL inputs also terminate in the ipsilateral dorsal portion of the descending octaval nucleus (dDO) in the goldfish. The dDO, which is the main first-order auditory nucleus in bony fishes, includes neurons that receive direct input from the otolithic end organs of the inner ear and project to the auditory midbrain. There are two groups of such auditory projection neurons: medial and lateral. The medial and the lateral groups in turn contain several neuronal populations, each of which includes one or more morphological cell types. In goldfish, the exclusively mechanos...
Source: Brain, Behavior and Evolution - August 18, 2016 Category: Neurology Source Type: research
Retinal Ganglion Cell Topography and Retinal Resolution in the Baikal Seal < b > < i > (Pusa sibirica) < /i > < /b >
The total number, size, topographic distribution, and cell density of ganglion cells were studied in retinal wholemounts of Baikal seals(Pusa sibirica). The ganglion cell size varied from 10 to 38 μm. A distinct cell group consisted of large ganglion cells of more than 30 μm in diameter. The topographic distribution of ganglion cells showed a definite area of high cell density similar to the area centralis of terrestrial carnivores. This area was located approximately 6-7 mm dorsotemporally of the geometric center of the wholemount. In this area, the peak cell densities in two wholemounts were 3,800 and 3,400 cells/mm2 (...
Source: Brain, Behavior and Evolution - August 16, 2016 Category: Neurology Source Type: research
Auditory Responses to Vocal Sounds in the Songbird Nucleus Taeniae of the Amygdala and the Adjacent Arcopallium
Many species of animals communicate with others through vocalizations. Over time, these species have evolved mechanisms to respond to biologically relevant vocal sounds via adaptive behaviors. Songbirds provide a good opportunity to search for the neural basis of this adaptation, because they interact with others through a variety of vocalizations in complex social relationships. The nucleus taeniae of the amygdala (TnA) is a structure located in the ventromedial arcopallium, which is akin to the mammalian medial amygdala. Studies on the anatomy and function of this nucleus have led to the speculation that the TnA is one o...
Source: Brain, Behavior and Evolution - August 16, 2016 Category: Neurology Source Type: research
Nucleus Ruber of Actinopterygians
Nucleus ruber is known as an important supraspinal center that controls forelimb movements in tetrapods, and the rubral homologue may serve similar functions in fishes (motor control of pectoral fin). However, two apparently different structures have been identified as ‘nucleus ruber' in actinopterygians. One is nucleus ruber of Goldstein (1905) (NRg), and the other nucleus ruber of Nieuwenhuys and Pouwels (1983) (NRnp). It remains unclear whether one of these nuclei (or perhaps both) is homologous to tetrapod nucleus ruber. To resolve this issue from a phylogen etic point of view, we have investigated the distribution o...
Source: Brain, Behavior and Evolution - August 9, 2016 Category: Neurology Source Type: research
