**Question:** Genu of internal capsule contains: (PGI June 2008)

**Core Concept:**
The internal capsule is a white matter tract located in the brain, connecting various brain regions and playing a crucial role in motor, sensory, and cognitive functions. It is divided into two segments: the genu and the splenium. The genu is involved in the connection between the corpus callosum and the limbic system, particularly the thalamus and the basal ganglia.

**Why the Correct Answer is Right:**
The genu of the internal capsule contains the thalamo-cortical fibers, which are crucial for transmitting sensory and motor information between the thalamus and the cerebral cortex. These fibers play a vital role in sensory and motor functions, as well as cognitive processing.

**Why Each Wrong Option is Incorrect:**
A. Option A (corpus callosum): The genu is not composed of corpus callosum fibers; it connects the thalamus and the basal ganglia, as explained above.
B. Option B (limbic system): While the genu is connected to the limbic system, it is not composed only of limbic system fibers. It is mainly composed of thalamo-cortical fibers.
C. Option C (cortical fibers): The genu of the internal capsule is composed of thalamo-cortical fibers, not cortical fibers.
D. Option D (basal ganglia): While the genu connects the basal ganglia to the thalamus and cortex, it is not composed exclusively of basal ganglia fibers.

**Clinical Pearl:**
The thalamo-cortical fibers in the genu of the internal capsule play a crucial role in sensory and motor functions, as well as cognitive processing. Understanding the anatomy and connectivity of this structure is essential for interpreting brain imaging studies and diagnosing conditions affecting the internal capsule, such as stroke or trauma.

**Correct Answer:** The genu of the internal capsule contains thalamo-cortical fibers.