Neuro Lab: Coronal Structures

Genu of the corpus callosum

Most anterior region of corpus callosum, provides interhemispheric connectivity to prefrontal cortex

Cingulum

Fibers running along the cingulate cortex.

Claustrum

Function still a mystery! perhaps involved in consciousness, focusing attention, or making decisions; most densely connected part of the brain by size

Internal capsule

Fibers that represent the output of cortex to the brainstem and spinal cord, and fibers streaming from thalamus toward the cortex.

Corona radiata

Fibers running from the internal capsule into the cerebral cortex.

External capsule

Fibers projecting from the neocortex to putamen.

Anterior commissure

Connects parts of the limbic system. Transfer of visual, auditory, and olfactory information between the temporal lobes

Rhinal fissure

Marks the horizontal boundary between the lateral and the ventral surfaces; the human correlate is the superior temporal sulcus

Extreme capsule

Part of the association fiber system that interconnects parts of the cerebral cortex.

Lateral olfactory tract

Carries olfactory information from olfactory bulb to the prepiriform and piriform olfactory cortex, and amygdalar cortical nuclei; recognition of individuals on the basis of their odor

Septohypothalamic tract

Originates from the septohypothalamic nucleus (at the anterior region of the hypothalamus and hear septal nuclei; involved in regulation of hormones, initiation of species-specific behaviors

Corpus callosum

Major interhemispheric connection; in humans contains 200-350 million axons

Caudate nucleus

These three subcortical nuclei are part of the basal ganglia. The basal ganglia are involved in facilitating movement, and also involved in higher-order cognitive processes. The caudate and putamen are often collectively referred to as the striatum. The caudate and putamen receive inputs from the cortex. The caudate nucleus is involved in initiation and termination of movement and implicated in Parkinson's disease (as it receives insufficient dopaminergic fibers from the substantia nigra). The globus pallidus is the main output of the basal ganglia. Other structures of the basal ganglia are the subthalamic nucleus and the substantia nigra.

Putamen

Globus pallidus

Optic chiasm

Fibers from the ganglion cells of the retina (optic nerve) cross to the contralateral side

Lateral ventricle

Cerebrospinal fluid (CSF) is generated into the ventricles by the choroid plexus. The lateral ventricles (I and II) are connected by the interventricular foramen. CSF flows into the IIIrd ventricle, and via the cerebral aqueduct it flows into the IVth ventricle. The central canal transports CSF within the spinal cord and is connected to the ventricular system of the brain.

Preoptic area

Septal nuclei

Involved in memory, learning, attention; hormone regulation; regulation of emotions such as fear, anxiety, and reward

Fornix

Output element of the hippocampus; projects to mammillary nuclei and septal nuclei. Can be broken into the body and the columns of fornix.

Fimbria

Output element of hippocampus; the fimbria forms the fornix once there is no more input from the hippocampus.

III ventricle

Amygdala

Assigning emotional value to experiences and objects.

Septum

The term refers to a partition. In the brain, the septum lies medially anterior to the thalamus, involved in limbic system and possibly in regulation of biologically relevant emotional and motivational behaviors.

Thalamus

Receives incoming sensory information and sends sensory information to relevant area of cortex.

Mammillo-thalamic tract

Output from the mammillary bodies to the limbic portions of the frontal lobe via the anterior thalamus.

Mammillary body

Receive input from the hippocampus via the fornix, send output to the limbic portions of the frontal lobe via the mammillothalamic tract; involved in memory functions.

Optic tract

Axons of retinal ganglion cells after they have passed the optic chiasm; most axons terminate in the lateral geniculate nucleus.

Hypothalamus

Biologically crucial functions, including activity cycles/sleep, reproductive behavior, thirst and feeding, aggression.

Hippocampus

Spatial mapping of environment, space within which concepts are organized.

Pineal gland

Produces melatonin; involved in sleep-wake and activity cycles.

Posterior commissure

Thought to play a role in the visual system, but functions are still largely unknown

Reticular formation

Complex network of brainstem nuclei, serves as a major integration and relay center for many vital brain systems to coordinate functions necessary for survival

Dentate gyrus

Consolidation of new memories, especially spatial and episodic memories; site of neurogenesis

Splenium

Most posterior region of corpus callosum, provides interhemispheric connectivity to temporal, parietal, and occipital lobes

Cerebral aqueduct

CSF flows into the IIIrd ventricle, and via the cerebral aqueduct it flows into the IVth ventricle.

Lateral geniculate nucleus

Receives fibers from ipsilateral eye and contralateral eye.

Superior colliculus

Directs eye movements in space.

Periaqueductal gray

Involved in descending pain modulation, regulation of heart rate and blood pressure, autonomic function (bladder control), production of vocalizations, and fearful and defensive reactions.

Optic radiations

White matter tracts, carry visual information from the lateral geniculate nucleus to the striate cortex (V1)

Inferior colliculus

Integration of auditory stimuli.

Medial longitudinal fasciculus

Nerve bundle responsible for extraocular eye muscle movements including saccadic eye movements and vestibular ocular reflex

Dorsal tegmental nucleus

Uses vestibular inputs to encode brain's head direction cell circuitry