Neuroscience through ages
What term describes the brain’s ability to reorganise and form new neural connections throughout life?
Neuroplasticity
A 68-year-old develops sudden right-sided weakness and expressive aphasia. Imaging shows an infarct involving the dominant frontal lobe. Which major cerebral artery is most likely affected?
Left middle cerebral artery.
Name the first-line drug class used to treat depression.
SSRIs (selective serotonin reuptake inhibitors)
Which neurotransmitter is the main inhibitory neurotransmitter in the brain?
GABA
“I begin in the retina. I leave the eye, partially cross with my colleagues at the optic chiasm, and most of us eventually synapse in a thalamic nucleus before reaching the occipital cortex. Who am I?”
Visual pathway / retinal ganglion cell pathway.
Anti-amyloid therapies for Alzheimer’s disease work by targeting which specific pathological protein?
Amyloid-beta
The immune system attacks the sheaths around axons in the central nervous system, so action potentials slow down or fail to propagate. Flare-ups are calmed with drugs that suppress inflammation.
multiple sclerosis
Diazepam and other benzodiazepines calm both anxiety and seizures. They do it by boosting which neurotransmitter
GABA
Which neurotransmitter, when low, is linked to depression?
Serotonin
“My cell body lies in the substantia nigra pars compacta. I release dopamine into the striatum and help regulate movement. When too many of us disappear, movement becomes slow and rigid.”
Nigrostriatal dopaminergic neuron.
In 1861, this French physician linked damage to the left inferior frontal gyrus with impaired speech production.
Paul Broca
Loss of neurons that make orexin, a hypothalamic chemical that keeps us awake, causes this disorder of uncontrollable sleep attacks.
narcolepsy
Name the drug class used to break down a clot in acute ischemic stroke.
tPA (tissue plasminogen activator)
Which neurotransmitter is depleted in Parkinson’s disease?
Dopamine
“I carry vibration, fine touch, and conscious proprioception from the lower limb. I ascend ipsilaterally through the spinal cord before synapsing in the medulla, and only then do I cross.”
Fasciculus gracilis / dorsal column–medial lemniscus pathway.
Name the large-scale research initiative that aims to map all neural connections in the human brain.
The Human Connectome Project
A fluid-filled cavity forms in the spinal cord. It first cuts the pain and temperature fibers crossing in front of the central canal, so pain and temperature sensation is lost over the shoulders and arms while vibration and proprioception are preserved. As it grows, it destroys the anterior horn cells and the hand muscles waste away.
Syringomyelia
Name the drug class used to slow cognitive decline in Alzheimer’s disease.
Acetylcholinesterase inhibitors
Which neurotransmitter is low in Alzheimer’s disease?
Acetylcholine
“I begin in the motor cortex, descend through the corona radiata and posterior limb of the internal capsule, pass through the cerebral peduncle and pyramids, and most of my fibres cross at the caudal medulla.”
Lateral corticospinal pathway.
This neuroscientist used silver staining to argue that the nervous system was composed of discrete individual cells rather than one continuous network.
Santiago Ramón y Cajal.
A mass pushes the midbrain across so that the cerebral peduncle on the opposite side is squeezed against the edge of the tentorium. The resulting weakness appears on the same side as the mass, which points to the wrong side of the brain.
Kernohans Notch phenomenon
Levodopa is typically co-administered with carbidopa in Parkinson’s treatment. Why?
Carbidopa inhibits peripheral breakdown of levodopa, allowing more levodopa to cross the blood-brain barrier and reducing peripheral side effects like nausea
Which excitatory neurotransmitter, when present in excess, is implicated in seizure activity and neuronal excitotoxicity?
Glutamate
“My cell body is in Clarke's nucleus. I carry unconscious proprioceptive information from the lower limb. I enter the cerebellum through the inferior cerebellar peduncle and, unlike many long CNS pathways, I never meaningfully abandon the side where I started.”
Dorsal spinocerebellar tract neuron/pathway.