21 research outputs found
Conserved Expression of the Glutamate NMDA Receptor 1 Subunit Splice Variants during the Development of the Siberian Hamster Suprachiasmatic Nucleus
Glutamate neurotransmission and the N-methyl-D-aspartate receptor (NMDAR) are central to photic signaling to the master circadian pacemaker located in the hypothalamic suprachiasmatic nucleus (SCN). NMDARs also play important roles in brain development including visual input circuits. The functional NMDAR is comprised of multiple subunits, but each requiring the NR1 subunit for normal activity. The NR1 can be alternatively spliced to produce isoforms that confer different functional properties on the NMDAR. The SCN undergoes extensive developmental changes during postnatal life, including synaptogenesis and acquisition of photic signaling. These changes are especially important in the highly photoperiodic Siberian hamster, in which development of sensitivity to photic cues within the SCN could impact early physiological programming. In this study we examined the expression of NR1 isoforms in the hamster at different developmental ages. Gene expression in the forebrain was quantified by in situ hybridization using oligonucleotide probes specific to alternatively spliced regions of the NR1 heteronuclear mRNA, including examination of anterior hypothalamus, piriform cortex, caudate-putamen, thalamus and hippocampus. Gene expression analysis within the SCN revealed the absence of the N1 cassette, the presence of the C2 cassette alone and the combined absence of C1 and C2 cassettes, indicating that the dominant splice variants are NR1-2a and NR1-4a. Whilst we observe changes at different developmental ages in levels of NR1 isoform probe hybridization in various forebrain structures, we find no significant changes within the SCN. This suggests that a switch in NR1 isoform does not underlie or is not produced by developmental changes within the hamster SCN. Consistency of the NR1 isoforms would ensure that the response of the SCN cells to photic signals remains stable throughout life, an important aspect of the function of the SCN as a responder to environmental changes in quality/quantity of light over the circadian day and annual cycle
Theory & Practice: Current Valuation Of Long Term Debt: A Proposal For Supplemental Disclosure
Altering Investment Decisions to Manage Financial Reporting Outcomes: Asset-Backed Commercial Paper Conduits and FIN 46
High-affinity transport of choline and amino acid neurotransmitters in synaptosomes from brain regions after lesioning the nucleus basalis magnocellularis of young and aged rats
Behavioral and adaptive status in an experimental model of Alzheimer's disease in rats
Ten days after bilateral electrolytic lesions of nucleus basalis magnocellularis (NBM) we tested behavioral (spontaneous motor activity, acquisition and performance of two-way active avoidance, fear-response in open field test, foot shock induced aggression, depression-response in learned helplessness test) and adaptive status (body temperature at standard, hot and cold environment as well as cold restraint-induced gastric lesions) in adult male Wistar rats. Compared to intact control and sham-operated rats, the bilateral NBM-lesioned rats showed the significant impairment of learning behavior and reduced fear, aggression and depression as well as altered body temperature at standard and stressed conditions. Namely, it was established that body temperature in NBM-lesioned rats was significantly lower at standard laboratory conditions, but in these rats body temperature significantly was raised after exposing to cold and hot environment. On the other hand, spontaneous motor activity and number and length of cold restraint-induced gastric lesions (erosions and petechiae) in NBM-lesioned rats were similarly to those in both controls. It could be concluded that NBM plays a significant role in cognitive, emotional and adaptive processes in the rats