D. G. Mytilinaios, K. I. Tsamis, S. J. Baloyannis
Laboratory of Neuropathology, 1st Department of Neurology, Aristotle University of Thessaloniki, Greece
The lateral hypothalamic area (LH) of human hypothalamus is the most prominent part of the lateral hypothalamic zone. The aims of the present study are: (1) to detail the dendritic morphology of Golgi impregnated neurons from the LH and (2) to describe and quantify the dendritic branching features, in an attempt to identify a cytoarchitectonic model for hypothalamic neurons and (3) to describe the OX1R immunoreactivity of lateral hypothalamic neurons. The study is based on 7 hypothalamus’ of young individuals who died accidently (Department of Forensic Medicine and Toxicology, Aristotle University of Thessaloniki). The impregnated neurons were analyzed with an image analysis software tool (ImageJ) for the following parameters: number of primary, secondary, tertiary and quartiary dendrites, length of each category of dendrites, total length of dendrites. Finally a Sholl analysis was performed.
Results:
1. The neuronal body protrude 2 or 3 primary dendrites (2-3) which are short in length (39.38±17.69μm).
2. The primary dendrites protrude 4 to 8 secondary dendrites (mean 5.56) which are rather long up to 175 μm (mean length 107.1) and with total length 580.91 ± 270 μm.
3. The total number of dendrites appears to be relatively uniform with mean number 14.16.
4. The Sholl analysis for neurons of Lateral Hypothalamic Nucleus demonstrates a rather uniform pattern of dendritic organization.
5. The large polyhedral neurons of lateral hypothalamic area are strongly immunopositive for OX1R and the receptors are located mainly in the cytoplasm of neurons.
Keywords: morphology, quantitative analysis, lateral hypothalamus, orexin receptors