Gender differences in the dendritic tree of granule neurons in the hippocampal dentate gyrus of weaning age rats

AbstractTraumatic brain injury (TBI) is a main cause of death and disabilities in young adults. Although learning and memory impairments are a major clinical manifestation of TBI, the consequences of TBI on the hippocampus are still not well understood. In particular, how lesions to the sensorimotor cortex damage the hippocampus, to which it is not directly connected, is still elusive. Here, we study the effects of sensorimotor cortex ablation (SCA) on the hippocampal dentate gyrus, by applying a highly sensitive gray-level co-occurrence matrix (GLCM) analysis. Using GLCM analysis of granule neurons, we discovered, in our TBI paradigm, subtle changes in granule cell (GC) morphology, including textual uniformity, contrast, and variance, which is not detected by conventional microscopy. We conclude that sensorimotor cortex trauma leads to specific changes in the hippocampus that advance our understanding of the cellular underpinnings of cognitive impairments in TBI. Moreover, we identified GLCM analysis as a highly sensitive method to detect subtle changes in the GC layers that is expected to significantly improve further studies investigating the impact of TBI on hippocampal neuropathology.

Download Full-text

Malfunctional Reorganization in the Developing Limbo-Prefrontal System in Animals: Implications for Human Psychoses?

Zeitschrift für Neuropsychologie ◽

10.1024//1016-264x.12.1.8 ◽

2001 ◽

Vol 12 (1) ◽

pp. 8-14

Author(s):

Gertraud Teuchert-Noodt ◽

Ralf R. Dawirs

Keyword(s):

Prefrontal Cortex ◽

Mental Disorders ◽

Dentate Gyrus ◽

Cognitive Functions ◽

Experimental Approach ◽

Regulatory Mechanisms ◽

Hippocampal Dentate Gyrus ◽

Non Invasive ◽

Invasive Method ◽

Activity Dependent

Abstract: Neuroplasticity research in connection with mental disorders has recently bridged the gap between basic neurobiology and applied neuropsychology. A non-invasive method in the gerbil (Meriones unguiculus) - the restricted versus enriched breading and the systemically applied single methamphetamine dose - offers an experimental approach to investigate psychoses. Acts of intervening affirm an activity dependent malfunctional reorganization in the prefrontal cortex and in the hippocampal dentate gyrus and reveal the dopamine position as being critical for the disruption of interactions between the areas concerned. From the extent of plasticity effects the probability and risk of psycho-cognitive development may be derived. Advance may be expected from insights into regulatory mechanisms of neurogenesis in the hippocampal dentate gyrus which is obviously to meet the necessary requirements to promote psycho-cognitive functions/malfunctions via the limbo-prefrontal circuit.

Download Full-text

Voltage-activated potassium currents in acutely dissociated hippocampal dentate gyrus neurons from neonatal rats

Developmental Brain Research ◽

10.1016/0165-3806(94)90316-6 ◽

1994 ◽

Vol 81 (2) ◽

pp. 309-313 ◽

Cited By ~ 6

Author(s):

Scott C. Baraban ◽

Eric W. Lothman

Keyword(s):

Dentate Gyrus ◽

Potassium Currents ◽

Neonatal Rats ◽

Hippocampal Dentate Gyrus

Download Full-text

Neuronal maturation in the hippocampal dentate gyrus via chronic oral administration of Artemisa annua extract is independent of cyclooxygenase 2 signaling pathway in diet-induced obesity mouse model

IBRO Reports ◽

10.1016/j.ibror.2019.07.1005 ◽

2019 ◽

Vol 6 ◽

pp. S325

Author(s):

Pan Soo Kim ◽

Dong-Hwa Choi ◽

Sang-Kyu Park ◽

Hyeok Jin Kwon ◽

Sun Shin Yi

Keyword(s):

Mouse Model ◽

Oral Administration ◽

Dentate Gyrus ◽

Signaling Pathway ◽

Cyclooxygenase 2 ◽

Neuronal Maturation ◽

Hippocampal Dentate Gyrus ◽

Diet Induced Obesity ◽

Artemisa Annua

Download Full-text

Increase in extracellular dopamine levels during clozapine-induced potentiation in the hippocampal dentate gyrus of chronically prepared rabbits

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y08-036 ◽

2008 ◽

Vol 86 (5) ◽

pp. 249-256 ◽

Cited By ~ 2

Author(s):

Takashi Kubota ◽

Itsuki Jibiki ◽

Akira Ishikawa ◽

Tomomi Kawamura ◽

Sonoko Kurokawa ◽

...

Keyword(s):

Electrical Stimulation ◽

Nmda Receptor ◽

Dentate Gyrus ◽

Negative Symptoms ◽

Clinical Effect ◽

Perforant Path ◽

Hippocampal Dentate Gyrus ◽

Extracellular Dopamine ◽

Stimulation Of ◽

Synaptic Responses

We previously found that 20 mg/kg clozapine i.p. potentiated the excitatory synaptic responses elicited in the dentate gyrus by single electrical stimulation of the perforant path in chronically prepared rabbits. We called this phenomenon clozapine-induced potentiation and proved that it was an NMDA receptor-mediated event. This potentiation is presumably related to clozapine’s clinical effect on negative symptoms and cognitive dysfunctions in schizophrenia. In the present study, to investigate the mechanisms underlying clozapine-induced potentiation, we examined whether extracellular dopamine and 5-HT levels changed during the potentiation by using a microdialysis technique in the dentate gyrus. The extracellular concentrations of dopamine and 5-HT levels were measured every 5 min during all experiments. Extracellular 5-HT levels did not change, but dopamine levels eventually increased significantly during clozapine-induced potentiation. The increase in the dopamine levels occurred almost simultaneously with the induction of clozapine-induced potentiation. These results suggest that clozapine-induced potentiation is at least partly attributable to a dopamine-mediated potentiation of excitatory synaptic transmission. The present study implies that such phenomena occur also in the perforant path–dentate gyrus pathway.

Download Full-text

Survival of mossy cells of the hippocampal dentate gyrus in humans with mesial temporal lobe epilepsy

Journal of Neurosurgery ◽

10.3171/2008.11.jns08779 ◽

2009 ◽

Vol 111 (6) ◽

pp. 1237-1247 ◽

Cited By ~ 17

Author(s):

László Seress ◽

Hajnalka Ábrahám ◽

Zsolt Horváth ◽

Tamás Dóczi ◽

József Janszky ◽

...

Keyword(s):

Temporal Lobe Epilepsy ◽

Dentate Gyrus ◽

Temporal Lobe ◽

Pyramidal Neurons ◽

Hippocampal Sclerosis ◽

Mesial Temporal Lobe Epilepsy ◽

Drug Resistant ◽

Hippocampal Dentate Gyrus ◽

Mossy Cells ◽

Mesial Temporal Lobe

Object Hippocampal sclerosis can be identified in most patients with mesial temporal lobe epilepsy (TLE). Surgical removal of the sclerotic hippocampus is widely performed to treat patients with drug-resistant mesial TLE. In general, both epilepsy-prone and epilepsy-resistant neurons are believed to be in the hippocampal formation. The hilar mossy cells of the hippocampal dentate gyrus are usually considered one of the most vulnerable types of neurons. The aim of this study was to clarify the fate of mossy cells in the hippocampus in epileptic humans. Methods Of the 19 patients included in this study, 15 underwent temporal lobe resection because of drug-resistant TLE. Four patients were used as controls because they harbored tumors that had not invaded the hippocampus and they had experienced no seizures. Histological evaluation of resected hippocampal tissues was performed using immunohistochemistry. Results Mossy cells were identified in the control as well as the epileptic hippocampi by using cocaine- and amphetamine-regulated transcript peptide immunohistochemistry. In most cases the number of mossy cells was reduced and thorny excrescences were smaller in the epileptic hippocampi than in controls; however, there was a significant loss of pyramidal cells and a partial loss of granule cells in the same epileptic hippocampi in which mossy cell loss was apparent. The loss of mossy cells could be correlated with the extent of hippocampal sclerosis, patient age at seizure onset, duration of epilepsy, and frequency of seizures. Conclusions In many cases large numbers of mossy cells were present in the hilus of the dentate gyrus when most pyramidal neurons of the CA1 and CA3 areas of the Ammon's horn were lost, suggesting that mossy cells may not be more vulnerable to epileptic seizures than the hippocampal pyramidal neurons.

Download Full-text