L10 Cerebellum

The group of nuclei in the thalamus responsible for relaying motor signals from the basal ganglia and cerebellum to the motor cortex.

A group of brain structures responsible for planning and selecting motor movements.

Part of the brain that controls coordination, balance, and smooth movements.

The network of pathways connecting the basal ganglia, thalamus, and motor cortex, responsible for controlling movement.

A pathway carrying sensory information about the body's position and movement from the spinal cord to the cerebellum.

A congenital malformation where the cerebellum is absent or underdeveloped, characterized by a small or missing vermis and enlarged cisterna magna.

The part of the cerebellum that connects to the spinal cord, mainly responsible for maintaining ongoing movements. It also receives blood supply from the superior cerebellar artery.

The part of the cerebellum that connects to the cerebrum and plays a role in planning and coordinating complex movements.

The part of the cerebellum that receives input from the vestibular system through the vestibular nerve and nuclei, playing a crucial role in balance and coordination.

A collection of nuclei deep within the cerebellum, involved in various cerebellar functions, including motor control, learning, and coordination.

The midline structure of the cerebellum, responsible for coordinating axial muscles, involved in posture and balance.

The white matter structure within the cerebellum, resembling a tree, responsible for communication between different cerebellar regions.

A group of nerve fibers connecting the cerebellum to the brainstem, responsible for transmitting information to and from other brain regions.

The part of the cerebellum responsible for coordinating movements of distal limbs, such as the arms and legs. It receives input from the lateral corticospinal tract.

The part of the cerebellum responsible for complex multilimb movements and hand-eye coordination. It receives input from the anterior corticospinal tract.

The superior cerebellar peduncle connects the cerebellum to the midbrain. It carries mostly efferent (outgoing) signals from the cerebellum to other brain regions.

The middle cerebellar peduncle connects the cerebellum to the pons. It carries mostly afferent (incoming) pontine fibers from the contralateral pons to the posterior lobe of the cerebellum.

The inferior cerebellar peduncle connects the cerebellum to the medulla. It carries sensory information about body position and movement from the spinal cord and brainstem to the cerebellum.

A type of ataxia characterized by uncoordinated trunk muscle movements, balance deficits, wide stance, and difficulty with eye movements.

A type of ataxia affecting lower limb movements, often caused by malnutrition or alcoholism.

A type of ataxia characterized by intention tremor, hypotonia, dysmetria, and dysdiadochokinesia. It is caused by lesions in the posterior lobe of the cerebellum.

Purkinje cells are a type of neuron found in the cerebellar cortex, responsible for coordinating movement and motor learning. They are characterized by their distinctive branched dendrites and their role in receiving input from various sources.

The apical dendrite of a Purkinje cell is a highly branched structure covered with spines. It extends towards the surface of the cerebellar cortex, where it receives input from parallel fibers and climbing fibers.

Parallel fibers are a type of axon that runs parallel to the folia (folds) of the cerebellar cortex. They synapse with the dendrites of Purkinje cells, providing excitatory input from the granule cells.

Climbing fibers are a type of axon that originates from the inferior olivary nucleus and travels to the cerebellar cortex. They synapse with the dendrites of Purkinje cells, providing a strong excitatory input that triggers a complex spike.

The simple spike is a type of action potential generated in Purkinje cells in response to excitatory input from parallel fibers.

The complex spike is a type of action potential in Purkinje cells triggered by a strong excitatory input from climbing fibers. It is characterized by a series of rapid spikes followed by a plateau phase.

Stellate and basket cells are inhibitory neurons found in the molecular layer of the cerebellar cortex. They synapse with the dendrites and axons of Purkinje cells, respectively, releasing GABA.

Lateral inhibition is a mechanism where the activity of one neuron inhibits the activity of neighboring neurons. In the cerebellar cortex, this occurs between Purkinje cells within the same mediolateral row.

A neurological disorder characterized by a lack of coordination, especially during voluntary movements. Patients often experience symptoms like a wide-based stance, gait ataxia, and difficulty with fine motor skills.

A type of tumor found in the roof of the fourth ventricle. It can result in ataxia by compressing the cerebellum.

A type of ataxia that affects the trunk of the body, leading to difficulties in coordinating movements and maintaining balance. Patients often stand with a wide-based stance.

Damage to the posterior lobe of the cerebellum, often caused by trauma, stroke, tumor, or degenerative diseases. Patients exhibit various symptoms, including limb ataxia, intention tremor, dysmetria, dysdiadochokinesia, and speech alterations.

A condition involving damage to the entire cerebellum, leading to widespread ataxia. It can result from various causes, including vitamin deficiencies, alcohol abuse, drugs, hyperthermia, and neurodegenerative diseases.

The most abundant cell type in the Central Nervous System (CNS) and the only excitatory cells located in the cerebellar cortex. They are responsible for sending out long axons, called parallel fibers, which excite Purkinje cells.

A pathway that originates in the spinal cord and ascends to the cerebellum. It delivers sensory information about the body's position and movement. Most mossy fibers in this pathway do not cross to the other side of the body and enter the cerebellum through the inferior cerebellar peduncle.

A pathway that originates in the cerebral cortex and descends to the cerebellum. It carries information about planned movements and motor control. The fibers in this pathway must cross to the other side of the body in the cerebral peduncles and enter the cerebellum through the middle cerebellar peduncle.

Fibers that originate in different parts of the brain, including the spinal cord and the cerebral cortex, and project to the granule cell layer of the cerebellar cortex. They synapse on the 'claws' of granule cells, which are specialized dendritic structures that receive the mossy fiber input.

Specialized dendritic structures that extend from the cell bodies of granule cells and receive input from mossy fibers in the granule cell layer. They play a crucial role in relaying signals from mossy fibers to parallel fibers which then excite Purkinje cells.

A type of inhibitory interneuron located in the molecular layer of the cerebellar cortex. It receives input from parallel fibers and synapses on Purkinje cell dendrites, playing a role in modulating Purkinje cell activity.

A type of inhibitory interneuron located in the molecular layer of the cerebellar cortex. It projects axons that wrap around the cell bodies of Purkinje cells, forming a basket-like structure. This arrangement allows basket cells to release neurotransmitters that can inhibit Purkinje cells.

A type of inhibitory interneuron located in the granule cell layer of the cerebellar cortex. It receives input from granule cells and synapses on their dendrites, playing a role in modulating the activity of granule cells.

The two parts of the brain involved in controlling movements.

The cerebellum smooths out movements, like a conductor leading an orchestra.

The basal ganglia 'select' which actions to take, like choosing a song to play.

The VA/VL nuclei of the thalamus are the relay stations for signals from the cerebellum and basal ganglia to the motor cortex.

The cerebellum is a small part of the brain, but it holds half of the brain's neurons.

Afferent pathway carrying proprioceptive information from the ipsilateral lower limb to the cerebellum, originating in Clarke's nucleus in the spinal cord.

Afferent pathway carrying proprioceptive information from the ipsilateral upper limb to the cerebellum, originating in the cuneate nucleus in the brainstem.

A mechanism that sends a copy of motor commands (efference) from the spinal cord to the cerebellum, informing it about the intended movement.

A pathway that carries proprioceptive information from the spinal cord to the cerebellum, originating in the intermediate zone of the spinal cord.

A pathway carrying proprioceptive information from the spinal cord to the cerebellum, originating in the intermediate zone and ventral gray horn of the spinal cord. It crosses the midline twice.

A collection of nuclei located deep within the cerebellum, involved in processing and integrating information from the cerebellar cortex and sending output to other brain regions.

The part of the cerebellum that coordinates movements of axial muscles, playing a crucial role in posture and balance.

The layer of the cerebellar cortex that contains Purkinje cells, the main output neurons of the cerebellum. It also contains various inhibitory interneurons that modulate Purkinje cell activity.

A collection of neurons located deep within the cerebellum, which receive input from Purkinje cells and project to other parts of the brain. They play a key role in coordinating motor movements and learning.

Climbing fibers are a type of excitatory input to Purkinje cells, originating in the inferior olivary nucleus and firing at high rates during learning but lower rates after the movement is learned.

Parallel fibers are a type of excitatory input to Purkinje cells, originating from granule cells and firing at a steady rate during both learned and unlearned movements.

When climbing fibers fire, they weaken the excitatory effect of parallel fibers on the Purkinje cell. This can be thought of as the Purkinje cell 'forgetting' the old pattern of the parallel fibers and learning a new one.

The deep cerebellar nuclei receive inhibitory input from Purkinje cells and project to the brainstem and thalamus, sending excitatory signals to help initiate movement.

The Purkinje cell is the primary output neuron of the cerebellar cortex, receiving input from both climbing and parallel fibers and sending inhibitory signals to deep cerebellar nuclei.

Purkinje cell inhibition of the deep cerebellar nuclei leads to smoother and more coordinated movements. This is analogous to an orchestra playing in harmony with the conductor's guidance.

The cerebellum receives sensory information about body position and movement through the spinocerebellar tract and planned movement information from the cerebral cortex through the corticopontocerebellar pathway.

Lesions in the cerebellar output fibers can cause ataxia, a lack of coordination, depending on the location of the lesion. For example, lesions near the midline can cause Benedikt’s Syndrome, while lesions more laterally can cause Claude’s Syndrome.

The fastigial nucleus is located in the vermis (medial) and receives input from the vestibular system. It helps maintain balance and upright posture.

The globose and emboliform nuclei, collectively known as the interposed nuclei, lie in the paravermis. They receive input from the cerebral cortex and spinal cord. Their function is to coordinate agonist and antagonist muscles at a single joint, contributing to smooth, coordinated movements.

The dentate nucleus sits in the lateral hemispheres of the cerebellum. It receives input from the cerebral cortex and is involved in planning and coordinating complex movements involving multiple joints. This includes things like reaching and combined digit movements.

Lesions to the fastigial nucleus can cause falls to the side of the lesion due to impaired balance and posture.

Lesions to the interposed nuclei (globose and emboliform) can cause an ipsilateral action tremor during voluntary movements, particularly when reaching or performing precise movements.

Lesions to the dentate nucleus can lead to multiple movement issues, including incoordination of digits and overshooting targets during reaching.

The middle cerebellar peduncle is the primary pathway for pontine fibers to reach the cerebellum. This pathway is crucial for transmitting information about planned movements and motor control from the cerebral cortex to the cerebellum.

The Cerebellar peduncles are responsible for connecting the cerebellum to the brainstem and transmitting information to and from other brain regions.

Coordinates distal limb muscles, like the arms and legs, to make smooth, precise movements. It receives input from the lateral corticospinal tract.

The three major subdivisions of the cerebellum are the vermis, paravermis, and lateral hemispheres.

The cerebellum serves a critical role in coordinating, smoothing, and refining movements. It receives input from both the cerebral cortex and the spinal cord.

The superior cerebellar peduncle is primarily an efferent pathway, sending information from the cerebellum to the midbrain.

Lesions to the vermis can cause truncal ataxia, characterized by a wide-based stance and difficulty with gait and speech.

The cerebellum is not essential for life, and people born with a non-functional cerebellum (Dandy-Walker Syndrome) can still learn motor patterns, albeit in the cerebrum instead.

Arnold-Chiari Malformation is a condition where cerebellar tonsils herniate down into the cervical spinal canal. It can affect lower cranial nerves and the medullary reticular formation.

The Inferior Olivary Nucleus, a friend of the cerebellum, provides climbing fibers that synapse with Purkinje cells and help with motor learning.

The Anterior Lobe of the cerebellum maintains ongoing movements, receives input from the spinal cord, and is supplied by the superior cerebellar artery.

The Posterior Lobe of the cerebellum receives inputs from the cerebral cortex and is involved in planning and coordinating more complex movements.

The "medial" nuclei of the cerebellum, receiving input from the vestibular system and controlling upright stance against gravity.

The "intermediate" nuclei of the cerebellum, located in the paravermis, which receive input from the cerebral cortex and spinal cord. They are crucial for coordination of agonist and antagonist muscles at single joints.

The "lateral" nuclei of the cerebellum, situated in the lateral hemispheres. They receive input from the cerebral cortex and are responsible for planning and coordinating complex movements involving multiple joints.

The cerebellum's only output neurons; information flows through them to reach other brain regions.

The cerebellum, unlike the cerebral cortex, has folds called folia instead of gyri. It also doesn't reach conscious awareness and primarily controls the same side of the body.

A layer in the cerebellar cortex containing Purkinje cells, the main output neurons of the cerebellum.

These deep nuclei are located within the cerebellum and receive input from Purkinje cells. They project to other brain regions, helping coordinate movements and learning.

These nuclei lie in the paravermis and receive input from the cerebral cortex and spinal cord. They coordinate the actions of agonist and antagonist muscles at a single joint to create smooth, coordinated movements.