Brain & Pathways of Movement
The embryonic brain develops through the enlargement of neural tube vesicles, first forming three primary vesicles and later five secondary vesicles.
Human Brain, Movement Disorders & Biomarkers
To understand my research, it’s important to first know the basics of brain circuits—complex networks that control movement and key functions. In healthy brains, these circuits ensure smooth motor coordination. But in Parkinson’s disease (PD) and dystonia, disruptions in these systems lead to movement problems. I’ve outlined some key insights into how brain circuits work normally and how they malfunction in PD and dystonia.
Movement Disorders
This classification highlights the differences between neurodegenerative disorders, which involve progressive degeneration of neurons, and non-neurodegenerative disorders, which may result from various causes and may not lead to progressive neuronal loss.
Neurotransmitters
The human brain consists of approximately 86 billion neurons that communicate through neurotransmission, where chemical messages called neurotransmitters are passed across the synapse, the gap between cells. These endogenous molecules are released from synaptic vesicles when a neuron is activated and interact with specific receptors on neighboring cells, influencing the strength of the signal transmitted in neural circuits.
Neurotransmitters (Amino Acid)
GABAergic neurons are a type of inhibitory neuron in the central nervous system (CNS) that primarily use gamma-aminobutyric acid (GABA) as their neurotransmitter. Glutamatergic neurons are a type of neuron that primarily release glutamate, the main excitatory neurotransmitter in the brain.
Neurotransmitters (Catecholamine)
The term “catecholamine” typically describes organic compounds that contain a catechol nucleus, characterized by a benzene ring with two adjacent hydroxyl groups, along with an amine group.
Dystonia - Biomarkers
There is currently no biomarker of dystonia and no gold-standard test for its diagnosis.
Parkinson’s disease - Biomarkers
Parkinson’s Disease (PD) is the second most common neurodegenerative disorder, characterized by the loss of dopaminergic neurons and the accumulation of aggregated α-synuclein, mainly in the substantia nigra pars compacta (SNpc) of the midbrain. The hallmark motor symptoms include tremor, bradykinesia, postural instability, and rigidity, often accompanied by non-motor issues such as dementia, depression, and psychosis. Protein biomarkers in Parkinson’s disease (PD) are critical for understanding disease mechanisms, early diagnosis, and developing therapeutic strategies.
Spiny Projection Neurons (SPN)
Striatal/Spiny Projection Neurons (SPNs), specifically Medium Spiny Neurons (MSNs), are a predominant type of neuron found in the striatum, which is part of the basal ganglia in the brain. SPNs primarily release the neurotransmitter GABA (gamma-aminobutyric acid), which is inhibitory. This means they decrease the likelihood of the firing of their target neurons.
Cerebral cortex
The cerebral cortex is the outermost layer of the brain, responsible for higher-order brain functions such as perception, cognition, and voluntary movement. It consists of several regions that are divided based on their location and function:
Subcortical region
The subcortical region of the brain consists of structures that lie beneath the cerebral cortex and play essential roles in regulating various functions, including movement, emotions, memory, and autonomic processes. Key subcortical structures include:
Substantia nigra
The substantia nigra is considered part of both the basal ganglia and the midbrain due to its anatomical location and its functional role within these brain systems. Here’s a breakdown of why it belongs to both: