Simple neural circuits and memory Flashcards
Lecture 7
Define dopamine and drug abuse.
Dopamine is a chemical released in the brain that makes you feel good. You can artificially activate neurons.
ICSS
Intracranial self-stimulation (ICSS) is a behavioral procedure in which operant responding is maintained by pulses of electrical brain stimulation.
What does ICCS do?
It activates dopaminergic pathways including the nucleas, accumbers and VTA.
What study relates to ICCS?
Brain stimulation reward was discovered in 1953 by James Olds and Peter Milner
Explain the reward system of the brain.
The human reward system. we get pleasure from that as they stimulate same part of the brain than sex and food.
The 3 parts of the brain when talking about this is ….
The prefrontal cortex, nucleas accumbens and the ventral tegmental area (VTA)
Define nucleas accumbens.
The nucleus accumbens is considered as the neural interface between motivation and action, playing a key role on feeding, sexual, reward, stress-related, drug self-administration behaviors, etc.
How much % of neurons in the VTA are dopaminergic.
About 50%
What is the VTA?
The ventral tegmental area (VTA) is well known for regulating reward consumption, learning, memory, and addiction behaviors through mediating dopamine (DA) release in downstream regions.
Define the reflex.
This is a simple automatic response to a stimulus. This is unlearned, subconscious, stereotyped.
Examples- swallowing and blinking
Monosynaptic stretch reflexes vs polysynaptic reflex
Mono- is the connection from muscles throughout spinal cord and then back to your muscles. Mono means one stretch. (knee doctor). In contrast, polysynaptic reflexes are mediated through at least two synapses and one interneuron.
Polysynaptic reflexes facts.
You can get conscious control over our reflexes not all reflexes are unconscious. These reflexes include, suckling, grasping and these are inherited by maturing brain but may be disinherited.
Explain synaptic excitation and inhibition.
Signals sent across excitatory synapses increase the activity of the receiving neuron, while signals sent across inhibitory synapses reduce neuron activity.
An increase in synaptic strength could be mediated by 3 things.
- an increase in neurotransmitter release.
- an increase in postsynaptic response.
- an increase in synaptic connections between neurons.
What is vestibulo- ocular reflex?
The vestibulo-ocular reflex (VOR) is a gaze stabilizing reflex: the sensory signals encoding head movements are transformed into motor commands that generate compensatory eye movements in the opposite direction of the head movement, thus ensuring stable vision. This is modifiable.
