Dose-dependent reductions in spatial learning and synaptic function in the dentate gyrus of adult rats following developmental thyroid hormone insufficiency

2006 ◽  
Vol 1069 (1) ◽  
pp. 10-22 ◽  
Author(s):  
M.E. Gilbert ◽  
Li Sui
Keyword(s):  
Thyroid Hormone ◽  
Dentate Gyrus ◽  
Spatial Learning ◽  
Synaptic Function ◽  
Adult Rats ◽  
Dose Dependent

scholarly journals Thyroid Hormone Insufficiency during Brain Development Reduces Parvalbumin Immunoreactivity and Inhibitory Function in the Hippocampus

Endocrinology ◽  
2007 ◽  
Vol 148 (1) ◽  
pp. 92-102 ◽  
Author(s):  
M. E. Gilbert ◽  
L. Sui ◽  
M. J. Walker ◽  
W. Anderson ◽  
S. Thomas ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Hormones ◽  
Brain Development ◽  
Dentate Gyrus ◽  
Perforant Path ◽  
High Dose ◽  
Synaptic Inhibition ◽  
Inhibitory Function ◽  
Inhibitory Circuitry ◽  
Dose Dependent

Thyroid hormones are necessary for brain development. γ-Amino-butyric acid (GABA)ergic interneurons comprise the bulk of local inhibitory circuitry in brain, many of which contain the calcium binding protein, parvalbumin (PV). A previous report indicated that severe postnatal hypothyroidism reduces PV immunoreactivity (IR) in rat neocortex. We examined PV-IR and GABA-mediated synaptic inhibition in the hippocampus of rats deprived of thyroid hormone from gestational d 6 until weaning on postnatal d 30. Pregnant dams were exposed to propylthiouracil (0, 3, 10 ppm) via the drinking water, which decreased maternal serum T4 by approximately 50–75% and increased TSH. At weaning, T4 was reduced by approximately 70% in offspring in the low-dose group and fell below detectable levels in high-dose animals. PV-IR was diminished in the hippocampus and neocortex of offspring killed on postnatal d 21, an effect that could be reversed by postnatal administration of T4. Dose-dependent decreases in the density of PV-IR neurons were observed in neocortex and hippocampus, with the dentate gyrus showing the most severe reductions (50–75% below control counts). Altered staining persisted to adulthood despite the return of thyroid hormones to control levels. Developmental cross-fostering and adult-onset deprivation studies revealed that early postnatal hormone insufficiency was required for an alteration in PV-IR. Synaptic inhibition of the perforant path-dentate gyrus synapse evaluated in adult offspring, in vivo, revealed dose-dependent reductions in paired pulse depression indicative of a suppression of GABA-mediated inhibition. These data demonstrate that moderate degrees of thyroid hormone insufficiency during the early postnatal period permanently alters interneuron expression of PV and compromises inhibitory function in the hippocampus.

PROTECTIVE EFFECTS OF VITAMIN C AGAINST CISPLATIN-INDUCED NEPHROTOXICITY AND LIPID PEROXIDATION IN ADULT RATS: A DOSE-DEPENDENT STUDY

2000 ◽  
Vol 41 (4) ◽  
pp. 405-411 ◽  
Author(s):  
LUSÂNIA M. GREGGI ANTUNES ◽  
JOANA D'ARC C. DARIN ◽  
MARIA DE LOURDES P. BIANCHI
Keyword(s):  
Lipid Peroxidation ◽  
Vitamin C ◽  
Protective Effects ◽  
Adult Rats ◽  
Dose Dependent

Dopamine in the hippocampal dentate gyrus modulates spatial learning via D1-like receptors

2019 ◽  
Vol 144 ◽  
pp. 101-107 ◽  
Author(s):  
Feixue Wang ◽  
Peng Wan ◽  
Weiyao Wang ◽  
Bin Xiao ◽  
Hua Jin ◽  
...  
Keyword(s):  
Dentate Gyrus ◽  
Spatial Learning ◽  
Hippocampal Dentate Gyrus

Prolonged protein deprivation differentially affects calretinin- and parvalbumin-containing interneurons in the hippocampal dentate gyrus of adult rats

2013 ◽  
Vol 555 ◽  
pp. 154-158 ◽  
Author(s):  
José Hipólito-Reis ◽  
Pedro Alberto Pereira ◽  
José Paulo Andrade ◽  
Armando Cardoso
Keyword(s):  
Dentate Gyrus ◽  
Protein Deprivation ◽  
Hippocampal Dentate Gyrus ◽  
Adult Rats

Selective Modulation of Tonic and Phasic Inhibitions in Dentate Gyrus Granule Cells

2002 ◽  
Vol 87 (5) ◽  
pp. 2624-2628 ◽  
Author(s):  
Zoltan Nusser ◽  
Istvan Mody
Keyword(s):  
Dentate Gyrus ◽  
Granule Cells ◽  
Cerebellar Granule Cells ◽  
Hippocampal Slices ◽  
Tonic Inhibition ◽  
Adult Rats ◽  
Adult Rat ◽  
Phasic Inhibition ◽  
The Mean

In some nerve cells, activation of GABAA receptors by GABA results in phasic and tonic conductances. Transient activation of synaptic receptors generates phasic inhibition, whereas tonic inhibition originates from GABA acting on extrasynaptic receptors, like in cerebellar granule cells, where it is thought to result from the activation of extrasynaptic GABAA receptors with a specific subunit composition (α6βxδ). Here we show that in adult rat hippocampal slices, extracellular GABA levels are sufficiently high to generate a powerful tonic inhibition in δ subunit–expressing dentate gyrus granule cells. In these cells, the mean tonic current is approximately four times larger than that produced by spontaneous synaptic currents occurring at a frequency of ∼10 Hz. Antagonizing the GABA transporter GAT-1 with NO-711 (2.5 μM) selectively enhanced tonic inhibition by 330% without affecting the phasic component. In contrast, by prolonging the decay of inhibitory postsynaptic currents (IPSCs), the benzodiazepine agonist zolpidem (0.5 μM) augmented phasic inhibition by 66%, while leaving the mean tonic conductance unchanged. These results demonstrate that a tonic GABAA receptor–mediated conductance can be recorded from dentate gyrus granule cells of adult rats in in vitro slice preparations. Furthermore, we have identified distinct pharmacological tools to selectively modify tonic and phasic inhibitions, allowing future studies to investigate their specific roles in neuronal function.

scholarly journals Effects of sleep deprivation on spatial learning and memory in juvenile and young adult rats.

2017 ◽  
Vol 10 (1) ◽  
pp. 109-116 ◽  
Author(s):  
Christopher P. Ward ◽  
Jessica I. Wooden ◽  
Ryan Kieltyka
Keyword(s):  
Young Adult ◽  
Sleep Deprivation ◽  
Learning And Memory ◽  
Spatial Learning ◽  
Spatial Learning And Memory ◽  
Adult Rats

scholarly journals Effects of early sensory deprivation on spatial learning in adult rats

2017 ◽  
Vol 62 (4) ◽  
pp. 256-260
Author(s):  
Natalia Kurzina ◽  
Irina Aristova ◽  
Anna Volnova
Keyword(s):  
Spatial Learning ◽  
Sensory Deprivation ◽  
Adult Rats

scholarly journals Endogenous H2S is required for hypoxic sensing by carotid body glomus cells

2012 ◽  
Vol 303 (9) ◽  
pp. C916-C923 ◽  
Author(s):  
Vladislav V. Makarenko ◽  
Jayasri Nanduri ◽  
Gayatri Raghuraman ◽  
Aaron P. Fox ◽  
Moataz M. Gadalla ◽  
...  
Keyword(s):  
Carotid Body ◽  
Time Course ◽  
Channel Blocker ◽  
Primary Site ◽  
Dependent Manner ◽  
Free Medium ◽  
Adult Rats ◽  
Glomus Cells ◽  
Dose Dependent ◽  
Carotid Body Glomus Cells

H2S generated by the enzyme cystathionine-γ-lyase (CSE) has been implicated in O2 sensing by the carotid body. The objectives of the present study were to determine whether glomus cells, the primary site of hypoxic sensing in the carotid body, generate H2S in an O2-sensitive manner and whether endogenous H2S is required for O2 sensing by glomus cells. Experiments were performed on glomus cells harvested from anesthetized adult rats as well as age and sex-matched CSE+/+ and CSE−/− mice. Physiological levels of hypoxia (Po2 ∼30 mmHg) increased H2S levels in glomus cells, and dl-propargylglycine (PAG), a CSE inhibitor, prevented this response in a dose-dependent manner. Catecholamine (CA) secretion from glomus cells was monitored by carbon-fiber amperometry. Hypoxia increased CA secretion from rat and mouse glomus cells, and this response was markedly attenuated by PAG and in cells from CSE−/− mice. CA secretion evoked by 40 mM KCl, however, was unaffected by PAG or CSE deletion. Exogenous application of a H2S donor (50 μM NaHS) increased cytosolic Ca2+ concentration ([Ca2+]i) in glomus cells, with a time course and magnitude that are similar to that produced by hypoxia. [Ca2+]i responses to NaHS and hypoxia were markedly attenuated in the presence of Ca2+-free medium or cadmium chloride, a pan voltage-gated Ca2+ channel blocker, or nifedipine, an L-type Ca2+ channel inhibitor, suggesting that both hypoxia and H2S share common Ca2+-activating mechanisms. These results demonstrate that H2S generated by CSE is a physiologic mediator of the glomus cell's response to hypoxia.

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