NETTER - Neuroscience Flash Cards

Coronal Sections through
the Forebrain: Midthalamus
1. Cingulum
2. Body of the lateral ventricle
3. Columns of the fornix
4. Thalamus
5. Lateral geniculate nucleus (LGN)
6. Medial geniculate nucleus (MGN)
7. Superior cerebellar peduncle
8. Body of the caudate nucleus
9. Stria terminalis
10. Third ventricle
11. Hippocampal formation
12. Middle cerebellar peduncle
13. Inferior cerebellar peduncle
Comment: Several thalamic nuclei in the posterior thalamus convey
visual and auditory information to specific regions of cerebral cortex.
The LGN receives segregated (nonbinocular) input via the optic
tract from the temporal hemiretina of the ipsilateral eye and nasal
hemiretina of the contralateral eye (representing the contralateral
visual field); the LGN further processes this information and conveys
it via the geniculocalcarine pathway (visual radiations) to area 17
on the calcarine fissure banks in the occipital cortex (primary visual
cortex). LGN damage can result in contralateral hemianopia. The
pulvinar receives visual input from the superior colliculus (which
receives visual information via the optic tract) and conveys this
information to areas 18 and 19 (visual association cortex) of the
occipital lobe. Damage to the pulvinar can result in contralateral
visual neglect. The MGN receives input from the inferior colliculus
via its brachium and from other brain stem auditory nuclei; this input
represents bilateral information. Damage to the MGN does not result
in unilateral (contralateral) deafness but may result in diminished
hearing with contralateral neglect in response to simultaneously
presented auditory stimuli.
Regional Neuroscience See book 13.17B