An Alternative Model of Laser-Induced Stroke in the Motor Cortex of Rats

Abstract

Background A common experimental rodent model for stroke includes induction by a technique in which middle cerebral artery is transiently (MCAO-t) or permanently (MCAO-p) occluded by catheterization. However, this model has prominent disadvantages which consist of the high variability of localization and size of the ischemic area, cases of intracranial hemorrhage and high mortality. Furthermore, the duration of a single MCAO operation takes about thirty minutes and requires highly trained staff. In this article, we propose an alternative method, which is based on laser-induced stroke in the motor cortex. In our research, we compared the original MCAO-p and MCAO-t models and a novel laser model. Results Compared with the impact of original MCAO-p and MCAO-t technique on brain tissue, the minimally invasive laser model demonstrated a decrease in: variability in body temperature, percent of infarcted volume, blood brain barrier breakdown and brain edema, as well as a prominent decrease of mortality and intracranial hemorrhage. Among other findings of this article, it can be noted that damage to the brain tissue in laser groups occurred only in the region of the motor cortex, without involving the striatal area. Conclusions The data presented in this paper show that the model of laser irradiation can serve as an effective method of inducible brain cortical infarction and may lead to a better understanding of the pathophysiology of ischemic stroke and the future development of new drugs and other neuro-protective agents.

A Novel Histological Technique to Assess Severity of Traumatic Brain Injury in Rodents: Comparisons to Neuroimaging and Neurological Outcomes

“…The lesion volume and brain edema were measured as a percentage of the total brain ( Boyko et al, 2019a ).…”

“…Right (injured) cerebral hemisphere edema was determined by calculating the volumes of both hemispheres from the total sum of coronal slice areas. The amount of swelling was calculated using the Kaplan method with this formula: extent of edema = (the volume of right hemisphere – the volume of left hemisphere) / the volume of left hemisphere ( Boyko et al, 2019a ).…”

A Novel Method for Assessing Cerebral Edema, Infarcted Zone and Blood-Brain Barrier Breakdown in a Single Post-stroke Rodent Brain

“…Brain edema was expressed as a percentage of the normal areas in the contralateral unaffected hemisphere. The extent of swelling was calculated using the Kaplan method: extent of edema = (the volume of right hemisphere – the volume of left hemisphere)/the volume of left hemisphere (Boyko et al, 2019a).…”

“…The slices were again scanned with an optical scanner. Infarct zone and brain edema was measured with the National Institutes of Health ImageJ software 1.37v (Boyko et al, 2011c, 2019a). For these measurements, the computer program converts the scan into a black and white image and then uses a threshold function to mask and calculate the pixels that are either black or white (see Figure 1).…”

“…Calculation of brain edema was performed by the RICH method. The calculation of brain edema by the RICH technique was done by comparing the contralateral and ipsilateral hemispheres, and performed using the following formula: Brain edema = (the volume of right hemisphere – the volume of left hemisphere)/the volume of left hemisphere (Boyko et al, 2019a).…”