Related Experiment Video
Updated: Jun 6, 2026
07:16
Methods for the Discovery of Novel Compounds Modulating a Gamma-Aminobutyric Acid Receptor Type A Neurotransmission
Published on: August 16, 2018
Study of neurovascular coupling by modulating neuronal activity with GABA
Harsha Radhakrishnan1, Weicheng Wu, David Boas
1MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA 02129, USA. harsha@nmr.mgh.harvard.edu
Brain Research
|December 15, 2010
Summary
The hemodynamic response is driven by later cortical processing, not initial thalamic input. This study used GABA to show that inhibiting secondary synaptic activity significantly reduces blood flow changes, highlighting cortico-cortical interactions.
Area of Science:
- Neuroscience
- Neurophysiology
- Vascular Biology
Background:
- Neurovascular coupling links neuronal activity to blood flow changes (functional hyperemia).
- Synaptic activity, not spiking, drives the hemodynamic response.
- The specific synaptic pathways responsible remain unclear.
Purpose of the Study:
- To differentiate between thalamocortical and cortico-cortical synaptic activity in driving the hemodynamic response.
- To investigate the role of secondary cortical processing in functional hyperemia.
Main Methods:
- Pharmacological manipulation using γ-aminobutyric acid (GABA) in the rat somatosensory cortex.
- Laminar electrophysiology to assess synaptic activity.
- Scalp electroencephalography (EEG) and diffuse optical imaging (DOI) to measure neural and vascular activity.
Main Results:
- GABA application reduced supragranular and infragranular synaptic activity but spared layer IV thalamic input (P1 SEP component).
- GABA significantly reduced subsequent cortical transmissions (N1 and P2 SEP components).
- Hemodynamic responses were strongly reduced, correlating with the diminished N1 and P2 components.
Conclusions:
- The hemodynamic response is primarily driven by cortico-cortical interactions.
- Initial thalamocortical activity in layer IV does not predominantly drive functional hyperemia.
- Secondary synaptic processing is critical for neurovascular coupling.
Related Concept Videos
01:18Antiepileptic Drugs: GABAergic Pathway Potentiators
γ-aminobutyric acid or GABA, plays a pivotal role as an inhibitory neurotransmitter in the brain. GABA pathway potentiators, also known as GABAergic drugs, are a class of pharmaceutical agents designed to enhance the functioning of the GABAergic system. These medications primarily treat epilepsy, a neurological disorder characterized by recurrent seizures.
The key GABA pathway potentiators used in epilepsy management are as follows.
Benzodiazepines are a well-known class of drugs used for their...
The key GABA pathway potentiators used in epilepsy management are as follows.
Benzodiazepines are a well-known class of drugs used for their...
01:29Excitatory and Inhibitory Effects of Neurotransmitters
When an action potential reaches the presynaptic axon terminal, it releases neurotransmitters from the neuron into the synaptic cleft at a chemical synapse. The released neurotransmitter can be excitatory or inhibitory. The critical criteria commonly used to determine whether a molecule is a neurotransmitter at a chemical synapse are the molecule's presence in the presynaptic neuron. Second, its release is in response to strong presynaptic depolarization. And lastly, the presence of specific...
01:20Antiepileptic Drugs: Modulators of Neurotransmitter Release Mediated by SV2A Protein
Antiepileptic drugs, such as levetiracetam (Keppra) and brivaracetam (Briviact), have emerged as crucial tools in managing epilepsy. These medications exert their therapeutic effects by targeting the synaptic vesicle protein SV2A, a transmembrane glycoprotein primarily found in the brain.
SV2A is a transmembrane glycoprotein located predominantly in the brain, modulating the release of neurotransmitters for neuronal communication. Both levetiracetam and brivaracetam exhibit a high affinity for...
SV2A is a transmembrane glycoprotein located predominantly in the brain, modulating the release of neurotransmitters for neuronal communication. Both levetiracetam and brivaracetam exhibit a high affinity for...
01:37Neural Regulation
Digestion begins with a cephalic phase that prepares the digestive system to receive food. When our brain processes visual or olfactory information about food, it triggers impulses in the cranial nerves innervating the salivary glands and stomach to prepare for food.
01:30Ligand-Gated Ion Channel Receptor: Gating Mechanism
Ligand-gated ion channels are transmembrane proteins that play a vital role in intercellular communication and functions of the nervous system. They allow the influx of ions across the membrane once the neurotransmitter binds, allowing the subsequent transmission of electrical excitation across the neurons. Other ligand-gated ion channels, like the γ-aminobutyric acid (GABA) receptor, permit anions like chloride into the cells on the binding of the GABA molecule. Their entry into the cell...
01:18Neural Regulation of Blood Pressure
The neural regulation of blood pressure involves intricate interactions between the autonomic nervous system (ANS) and cardiovascular system, ensuring adequate perfusion of tissues. This regulation primarily occurs through baroreceptor and chemoreceptor reflexes, involving both short-term and long-term mechanisms.
Baroreceptor Reflex
Baroreceptors, located in the carotid sinuses and aortic arch, detect changes in blood pressure. When blood pressure rises, these stretch-sensitive receptors...
Baroreceptor Reflex
Baroreceptors, located in the carotid sinuses and aortic arch, detect changes in blood pressure. When blood pressure rises, these stretch-sensitive receptors...