Expression of MicroRNA-200a/b/c in the Mediobasal Hypothalamic Nuclei with Aging.

Background: MicroRNAs (miRNAs) belong to small non-coding RNAs that coordinate the expression of cellular genes at the post-transcriptional level. The hypothalamus is a key regulator of homeostasis, biological rhythms and adaptation to different environmental factors. It also participates in the aging regulation.

Ontogenetic Changes in the Expression of the Lin28 Protein in the Rat Hypothalamic Tuberal Nuclei.

The hypothalamus is a primary regulator of homeostasis, biological rhythms and adaptation to different environment factors. It also participates in the aging regulation. The expression of neurons containing Lin28 was studied by immunohistochemistry in male rats aged 2, 6, 12, and 24 months in the tuberal region of the rat hypothalamus.

Changes of discharge properties of neurons from dorsomedial hypothalamic nuclei during aging in rats.

The hypothalamus is a vital brain center that is participated in the integration of the endocrine and nervous systems and control of the homeostasis and aging. Spontaneous firing activity from single neurons of the dorsomedial hypothalamic nucleus (DMN) was studied extracellularly in vivo in urethane-anaesthetized rats. The discharge patterns of the majority of DMN neurons were irregular, including periods of relatively stable activity interrupted by pauses.

Expression of calbindin and calretinin in the dorsomedial and ventromedial hypothalamic nuclei during aging.

The hypothalamus is involved in the regulation of rhythms, autonomic, endocrine, and behavioral functions and may also participate in aging development and control. The aim of this work was to study the expression of calbindin (CB) and calretinin (CR) in the ventromedial (VMH) and dorsomedial (DMH) hypothalamic nuclei in young and old rats of both sexes by immunohistochemistry and western blotting. In young animals, the largest number of CB-immunoreactive (IR) neurons was detected in the ventral part of DMH (DMHv) and smaller percentage was found in its dorsal part (DMHd), in the dorsomedial part of the VMH (VMHdm) and in the ventrolateral part of the VMH (VMHvl).

Changes of nNOS expression in the tuberal hypothalamic nuclei during ageing.

The hypothalamus is the most important integrator of autonomic and endocrine regulation in the body and it also has a fundamental role in ageing development and lifespan control. In order to better understand the role of NO-ergic system in the hypothalamic regulation of ageing, the purpose of this study was to investigate the expression of neuronal nitric oxide synthase (nNOS) in the arcuate (ARC), ventromedial (VMH) and dorsomedial (DMH) hypothalamic nuclei in young (2-3-month-old) and old (24-month-old) male and female rats using immunohistochemistry and western blot analysis. In young animals, only single nNOS-immunoreactive (IR) neurons were detected in ARC, and nNOS-IR neurons were found in the VMH (19 ± 3.

Development of nNOS-positive preganglionic sympathetic neurons in the rat thoracic spinal cord.

To gain a better understanding of the neuroplasticity of sympathetic neurons during postnatal ontogenesis, the distribution of neuronal nitric oxide synthase (nNOS) immunoreactivity was studied in sympathetic preganglionic neurons (SPN) in the spinal cord (Th2 segment) of female Wistar rats at different ages (newborn, 10-, 20-, 30-day-old; 2-, 6-month-old; 3-year-old). In all age groups, the majority of nNOS-immunoreactive (IR) neurons was observed in the nucleus intermediolateralis thoracolumbalis pars principalis. In the first month, the proportion of nNOS-IR neurons decreased significantly from 92 ± 3.

Development of nNOS-positive neurons in the rat sensory ganglia after capsaicin treatment.

To gain a better understanding of the neuroplasticity of afferent neurons during postnatal ontogenesis, the distribution of neuronal nitric oxide synthase (nNOS) immunoreactivity was studied in the nodose ganglion (NG) and Th2 and L4 dorsal root ganglia (DRG) from vehicle-treated and capsaicin-treated female Wistar rats at different ages (10-day-old, 20-day-old, 30-day-old, and two-month-old). The percentage of nNOS-immunoreactive (IR) neurons decreased after capsaicin treatment in all studied ganglia in first 20 days of life, from 55.4% to 36.