Striatum

Striatum

Cortical surface with an overlay of the basal ganglia and thalamus

The striatum is a subcortical part of the forebrain and a critical component of the basal ganglia. It is involved in various functions, including motor and action planning, decision-making, motivation, reinforcement, and reward perception.

Anatomy

Structural MRI of the striatum

The striatum is divided into two main parts: the caudate nucleus and the putamen. These structures are separated by the internal capsule but are functionally interconnected. The striatum is the primary input nucleus of the basal ganglia system, receiving glutamatergic and dopaminergic inputs from various cortical and subcortical structures.

Caudate Nucleus

The caudate nucleus is a C-shaped structure that follows the lateral ventricle. It is involved in various higher neurological functions, including learning and memory.

Putamen

The putamen is a round structure located at the base of the forebrain. It is primarily involved in motor control and influences various types of learning.

Function

Dendritic spines in the striatum

The striatum plays a crucial role in the modulation of movement and various cognitive processes. It is involved in the regulation of voluntary motor control, procedural learning, and habit formation. The striatum is also a key player in the reward system, influencing motivation and reinforcement learning.

Basal Ganglia Circuits

Diagram of the basal ganglia

The striatum is part of the basal ganglia circuits, which include the globus pallidus, substantia nigra, and subthalamic nucleus. These circuits are involved in the regulation of movement and are implicated in various neurological disorders such as Parkinson's disease and Huntington's disease.

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Basal ganglia circuits

Role in Reward and Motivation

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Overview of reward structures in the human brain

The striatum is a central component of the brain's reward system. It processes information related to reward and motivation, influencing decision-making and goal-directed behavior. Dopaminergic neurons from the ventral tegmental area project to the striatum, modulating its activity in response to rewarding stimuli.

Clinical Significance

The striatum is implicated in several neurological and psychiatric disorders. Dysfunction in the striatum can lead to movement disorders such as Parkinson's disease, characterized by the degeneration of dopaminergic neurons. It is also involved in psychiatric conditions such as schizophrenia and addiction, where alterations in striatal function affect behavior and cognition.

Imaging

Coronal sections of the striatum

Sagittal sections of the striatum

Advanced imaging techniques such as MRI and PET scans are used to study the structure and function of the striatum. These techniques help in understanding the role of the striatum in health and disease, providing insights into its involvement in various neurological and psychiatric conditions.

Related Pages

• Basal ganglia
• Caudate nucleus
• Putamen
• Globus pallidus
• Substantia nigra
• Subthalamic nucleus
• Parkinson's disease
• Huntington's disease