developing-behavioral-box-for-assessing-prepulse-inhibition-neural

Developing a Behavioral Box for Assessing Prepulse Inhibition and Neural Activity in Psychiatric Animal Models

Early-life distress is recognized as a potential precursor to neurodevelopmental disorders. One approach to investigating this condition in animal models ...

Santos Dumont Institute

Excitotoxicity is the major component in neuropathological conditions, related to harmful action of imbalanced concentrations of glutamate and its agonists in the nervous tissue, ultimately resulting in cell death. In the present study, we evaluated the effects of an acute striatal lesion induced by a focal N-methyl-D-aspartate (NMDA) microinjection on the morphometry of NADPH diaphorase-reactive neurons (NADPH-d ), a subset of cells which release nitric oxide (NO) in the brain and are known by its resistance in pathological conditions. Two hundred and forty NADPH-d neurons from NMDA-lesioned striatum and contralateral counterpart were tridimensionally reconstructed at 1, 3 and 7 post-lesion days (PLDs). Cell body and dendritic field areas, length of dendrites by order and fractal dimension were analyzed. There were no significant morphometric differences when NADPH-d neurons from lesioned and control striatal regions were compared among PLDs evaluated. Conversely, a conspicuous pallor in striatal neuropil reactivity was evidenced, especially in latter survival time. In addition, we observed a noticeable inflammatory response induced by NMDA. Our results suggest that NADPH-d neurons were spared from deleterious effects of acute NMDA excitotoxic damage in the striatum, reinforcing the notion that this cell group is selectively resistant to injury in the nervous system.

Morphometric analysis of NADPH diaphorase reactive neurons in a rat model of focal excitotoxic striatal injury.

Neuroscience research uses neurosurgery in animal models for several experimental techniques. To our knowledge, there is no published method for small animal neurosurgery training. Based on the similar thickness of chicken eggshells and mouse, rat, and some small primate skulls, here we propose an egg model training protocol for stereotaxic surgery.

Egg Model Training Protocol for Stereotaxic Neurosurgery and Microelectrode Implantation.

Current available therapies for Parkinson disease (PD) have strong limitations, and patients usually present with refractory symptoms despite all efforts. Deep brain stimulation (DBS), which has been used in PD patients for decades (since 1987), has best indications for symptoms like tremor, motor fluctuations, or dyskinesia. However, postural instability and gait disturbances (PIGD) have restricted benefits with DBS. In 2009, spinal cord stimulation (SCS), a well-established therapy for chronic pain, has emerged as a potential alternative therapy that may help control unresponsive symptoms such as bradykinesia, PIGD, and freezing of gait.

History of and Insights Into Spinal Cord Stimulation in Parkinson Disease.

 Clinical impact of transcranial direct current stimulation (tDCS) alone for Parkinson's disease (PD) is still a challenge. Thus, there is a need to synthesize available results, analyze methodologically and statistically, and provide evidence to guide tDCS in PD.  Investigate isolated tDCS effect in different brain areas and number of stimulated targets on PD motor symptoms.  A systematic review was carried out up to February 2021, in databases: Cochrane Library, EMBASE, PubMed/MEDLINE, Scopus, and Web of science. Full text articles evaluating effect of active tDCS (anodic or cathodic) vs. sham or control on motor symptoms of PD were included.  Ten studies ( = 236) were included in meta-analysis and 25 studies ( = 405) in qualitative synthesis. The most frequently stimulated targets were dorsolateral prefrontal cortex and primary motor cortex. No significant effect was found among single targets on motor outcomes: Unified Parkinson's Disease Rating Scale (UPDRS) III - motor aspects (MD = -0.98%, 95% CI = -10.03 to 8.07,  = 0.83,   = 0%), UPDRS IV - dyskinesias (MD = -0.89%, CI 95% = -3.82 to 2.03,  = 0.55,   = 0%) and motor fluctuations (MD = -0.67%, CI 95% = -2.45 to 1.11,  = 0.46,   = 0%), timed up and go - gait (MD = 0.14%, CI 95% = -0.72 to 0.99,  = 0.75,   = 0%), Berg Balance Scale - balance (MD = 0.73%, CI 95% = -1.01 to 2.47,  = 0.41,   = 0%). There was no significant effect of single vs. multiple targets in: UPDRS III - motor aspects (MD = 2.05%, CI 95% = -1.96 to 6.06,  = 0.32,   = 0%) and gait (SMD = -0.05%, 95% CI = -0.28 to 0.17,  = 0.64,   = 0%). Simple univariate meta-regression analysis between treatment dosage and effect size revealed that number of sessions (estimate = -1.7, SE = 1.51, z-score = -1.18,  = 0.2, IC = -4.75 to 1.17) and cumulative time (estimate = -0.07, SE = 0.07, z-score = -0.99,  = 0.31, IC = -0.21 to 0.07) had no significant association.  There was no significant tDCS alone short-term effect on motor function, balance, gait, dyskinesias or motor fluctuations in Parkinson's disease, regardless of brain area or targets stimulated.

Article	Year
Morphometric analysis of NADPH diaphorase reactive neurons in a rat model of focal excitotoxic striatal injury. Neuropathology : official journal of the Japanese Society of Neuropathology\| PubMed ID: 27238870	2016
Egg Model Training Protocol for Stereotaxic Neurosurgery and Microelectrode Implantation. World neurosurgery\| PubMed ID: 29277591	2018
History of and Insights Into Spinal Cord Stimulation in Parkinson Disease. Neurorehabilitation and neural repair\| PubMed ID: 33048030	2020
Transcranial Direct Current Stimulation on Parkinson's Disease: Systematic Review and Meta-Analysis. Frontiers in neurology\| PubMed ID: 35082749	2021

Hougelle Simplicio

Biography

JoVE Journal Publications

Other Publications