**1. Introduction**

The cerebrovascular system refers to the transport of blood to and from the brain. Ischemia is a condition initiated with reduced blood flow to the brain regions affecting its normal function. Reperfusion injury, also called Ischemic reperfusion injury, is defined as illogical damage to cells post-restoration of blood flow to ischemic cells.

Cerebrovascular disorders (CVD) comprise a group of signs, symptoms, and damage mechanisms in the brain tissue cells. The damage is associated with various blood supply abnormalities that include haemorrhage, blockage or malformation that prevent brain cells from receiving enough blood supply leading to cerebrovascular disorder. CVD has a transient ischemic attack, aneurysm, stroke and vascular malformation [1]. CVD manifests as acute accidents (commonly known as stroke), which may be either ischemic or haemorrhagic, where the outcome ranges from complete recovery to immediate death.

Cerebral reperfusion injury is a condition where ischemia is worsened but protects the brain tissue after reperfusion. Thrombolysis and embolectomy are considered important contributors to reperfusion injury. Thus, understanding reperfusion injury is essential to know possible diagnosis and treatment of stroke [2].

Cerebrovascular disease (CVD) or stroke are leading causes of morbidity and mortality in humans. In 2001 it was estimated that approximately around 5.5 million deaths were due to stroke [3]. In Europe, about 1 million deaths were due to stroke in the year 2015 [4]. Studies suggest that stroke is the fifth major cause of death in the USA [5]. Certain studies reveal that 15 million people are affected by stroke every year; about 6 million have died. Throughout the western world, stroke is a cause of death of 10 to 12% of its population [6]. Reports conclude that CVD people are about 13–33 people per one lac population in India [7]. Stroke is associated with risk factors such as sex, age, lifestyle, smoking, alcohol, diet and physiological characteristics such as fibrinogen, serum cholesterol and high blood pressure [8]. Research has revealed that high blood pressure is the most critical risk factor contributing to 50% of ischemic stroke [9]. The use of tobacco increases the risk of hemorrhagic stroke by two-fold [10].

Treatment of stroke is mainly focused on improving blood supply, decreasing the severity of brain tissue injuries. Few clinical studies have revealed that reperfusion after thrombolysis has improved clinical outcome in few patients with stroke. Still, in a few patients, reperfusion has worsened the condition by causing fatal edema and intracranial haemorrhage following thrombolysis [2]. Cerebrovascular disease is an age-linked disease with severe vascular complications and comorbidities. Therefore there is an urgency to develop different therapeutic approaches to treat the disease. Thus, researchers could focus on Animal models which reproduce similar pathophysiological condition of human stroke. These animal models support emerging new strategies for stroke treatment in humans. This chapter explains in detail different rodents models for cerebral ischemia along with their advantages and disadvantages.
