neuropeptide-y and cresyl-violet

Detailed neuropathological studies of the extent of hippocampal sclerosis (HS) in epilepsy along the longitudinal axis of the hippocampus are lacking. Neuroimaging studies of patients with temporal lobe epilepsy support that sclerosis is not always localised. The extent of HS is of relevance to surgical planning and poor outcomes may relate to residual HS in the posterior remnant. In 10 post mortems from patients with long histories of drug refractory epilepsy and 3 controls we systematically sampled the left and right hippocampus at seven coronal anatomical levels along the body to the tail. We quantified neuronal densities in CA1 and CA4 subfields at each level using Cresyl Violet (CV), calretinin (CR), calbindin (CB) and Neuropeptide Y (NPY) immunohistochemistry. In the dentate gyrus we graded the extent of granule cell dispersion, patterns of CB expression, and synaptic reorganisation with CR and NPY at each level. We identified four patterns of HS based on patterns of pyramidal and interneuronal loss and dentate gyrus reorganisation between sides and levels as follows: (1) symmetrical HS with anterior-posterior (AP) gradient, (2) symmetrical HS without AP gradient, (3) asymmetrical HS with AP gradient and (4) asymmetrical cases without AP gradient. We confirmed in this series that HS can extend into the tail. The patterns of sclerosis (classical versus atypical or none) were consistent between all levels in less than a third of cases. In conclusion, this series highlights the variability of HS along the longitudinal axis. Further studies are required to identify factors that lead to focal versus diffuse HS.

Topics: Adult; Aged; Aged, 80 and over; Benzoxazines; CA1 Region, Hippocampal; Calbindin 2; Calbindins; Cell Count; Coloring Agents; Dentate Gyrus; Epilepsy, Temporal Lobe; Female; Humans; Interneurons; Male; Middle Aged; Neuropeptide Y; Oxazines; Pyramidal Cells; S100 Calcium Binding Protein G; Sclerosis

Trimethyltin (TMT) is an organic metal known to induce neuronal degeneration in the hippocampus, and abnormal behavior characterized by seizures, increased aggression and memory deficits. We administered TMT to rats and studied the changes of neuropeptide Y (NPY) and somatostatin (SOM) in the hippocampus. Phenobarbital (PB) was administered as an anticonvulsant to assess the effect of seizures on neuropeptide expressions in both dorsal and ventral hippocampus. Histochemically, NPY-immunoreactivity increased 4 days after TMT treatment in the hilus of the hippocampus, then progressively decreased and dropped to a level below control 16 days after TMT treatment. Detection of NPY mRNA by in situ hybridization preceded the detection of NPY by immunohistochemistry. NPY mRNA signals increased in the hilus 2 days after TMT treatment. SOM-immunoreactivity also increased in the hilus of the hippocampus 2 days after TMT treatment, then decreased rapidly to a normal level. Similar changes in SOM mRNA were demonstrated by in situ hybridization. PB treatment significantly inhibited changes of NPY in terms of both immunoreactivity and mRNA expression; however, the same treatment failed to affect changes in SOM expression. This suggests that NPY and SOM act by different mechanisms in TMT-induced neurodegeneration.

Topics: Animals; Anticonvulsants; Benzoxazines; Cell Count; Coloring Agents; Hippocampus; Immunohistochemistry; In Situ Hybridization; Male; Neuropeptide Y; Oxazines; Phenobarbital; Rats; Rats, Sprague-Dawley; RNA, Messenger; Seizures; Somatostatin; Trimethyltin Compounds

The structural organization of the lamprey extratelencephalic forebrain is re-examined from the perspective of the prosomeric segmental paradigm. The question asked was whether the prosomeric forebrain model used for gnathostomes is of material advantage for interpreting subdivisions in the lamprey forebrain. To this aim, the main longitudinal and transverse landmarks recognized by the prosomeric model in other vertebrates were identified in Nissl-stained lamprey material. Lines of cytoarchitectural discontinuity and contours of migrated neuronal groups were mapped in a two-dimensional sagittal representation and were also classified according to their radial position. Immunocytochemical mapping of calretinin expression in adjacent sections served to define particular structural units better, in particular, the dorsal thalamus. These data were complemented by numerous other chemoarchitectonic observations obtained with ancillary markers, which identified additional specific formations, subdivisions, or boundaries. Emphasis was placed on studying whether such chemically defined neuronal groups showed boundaries aligned with the postulated inter- or intraprosomeric boundaries. The course of diverse axonal tracts was studied also with regard to their prosomeric topography. This analysis showed that the full prosomeric model applies straightforwardly to the lamprey forebrain. This finding implies that a common segmental and longitudinal organization of the neural tube may be primitive for all vertebrates. Interesting novel aspects appear in the interpretation of the lamprey pretectum, the dorsal and ventral thalami, and the hypothalamus. The topologic continuity of the prosomeric forebrain regions with evaginated or non-evaginated portions of the telencephalon was also examined.

Topics: Acetylcholinesterase; Animals; Benzoxazines; Brain Mapping; Calbindin 2; Dopamine; Galanin; gamma-Aminobutyric Acid; Histamine; Immunohistochemistry; Lampreys; Microscopy, Electron, Scanning; Neuropeptide Y; Oxazines; Prosencephalon; S100 Calcium Binding Protein G; Serotonin; Substance P; Vasotocin

To further the understanding of gastrointestinal function in this species, and in particular to advance our own work concerning central emetic pathways, the cytoarchitecture and the distribution of eight neurochemicals were studied in the ferret dorsal vagal complex (DVC; area postrema, nucleus of the solitary tract [nTS] and dorsal motor nucleus of the vagus). The cytoarchitectural features of this region in the ferret were similar to those seen in other species; however, the ferret possesses a particularly large and distinct subnucleus gelatinosus of the nTS. Dense calcitonin gene-related peptide-immunoreactivity was found in the gelatinous, interstitial and commissural subnuclei of the nTS, with lesser amounts in other regions of the DVC. Enkephalin-immunoreactivity of varying densities was found throughout the DVC. Moderate to dense galanin-immunoreactivity was observed throughout the DVC, with the exception of the subnucleus gelatinosus of the nTS, from which it was virtually absent. Dense neuropeptide Y-immunoreactivity was observed in the subnucleus gelatinosus and interstitial subnucleus, with moderate staining in other regions of the DVC. Neurotensin immunoreactivity was very sparse or absent. Immunoreactivity for serotonin was sparsely distributed throughout the DVC. Moderate somatostatin-immunoreactivity was observed over a large portion of the DVC, but was virtually absent from the gelatinosus and interstitial subnuclei. Substance P immunoreactivity was observed throughout the DVC and was particularly dense in the dorsal/dorsolateral subnucleus and the dorsal aspects of the medial and commissural subnuclei. In terms of its cytoarchitecture the DVC of the ferret is more similar to the cat than the rat, especially with regard to the area postrema and the subnucleus gelatinosus of the nTS. The distribution of neuroactive substances was largely similar to other species; however, differences were present particularly in patterns of immunoreactivity for enkephalin, serotonin, neuropeptide Y and somatostatin.

Topics: Animals; Benzoxazines; Biomarkers; Cats; Coloring Agents; Enkephalins; Ferrets; Galanin; Immunohistochemistry; Indoles; Male; Medulla Oblongata; Neuropeptide Y; Neuropeptides; Neurotensin; Oxazines; Rats; Serotonin; Solitary Nucleus; Somatostatin; Species Specificity; Vagus Nerve

In a previous study we described abnormalities in cytoarchitecture and vasoactive intestinal polypeptide distribution in the suprachiasmatic nucleus (SCN) of anophthalmic mice. However, the effect of anophthalmia on the geniculohypothalamic pathway, an important pathway for relay of photic information to the SCN, is not known. The present study examined the geniculohypothalamic pathway in congenitally anophthalmic and sighted control mice. The data demonstrate that the development of an intergeniculate leaflet (IGL), the expression of neuropeptide Y (NPY) by IGL neurons and the formation of NPY terminal fields in the SCN proceed in the absence of retinal input. Although the cytoarchitectural organization of the anophthalmic IGL differs from that of the control mouse, the distribution of NPY plexuses in the suprachiasmatic nucleus is remarkably similar.

Topics: Animals; Anophthalmos; Benzoxazines; Geniculate Bodies; Histocytochemistry; Hypothalamus; Mice; Mice, Inbred Strains; Neural Pathways; Neuropeptide Y; Oxazines; Retina; Suprachiasmatic Nucleus