Hippocampus
The hippocampus is responsible for the formation of
short-term and long-term memory. In
addition, it plays an important role in spatiotemporal
orientation. The hippocampus is
bordered ventrally by the thalamus and dorsally by the
corpus callosum. While the
hippocampus is completely covered by the cerebrocortical
mantle, it is separated from the
cortex by white matter.
Olfactory Bulb
The mouse olfactory bulb is a designated region to receive,
integrate and transmit olfactory
information. Olfaction is behaviorally the most
important sense for mice and this is
reflected in the comparatively large (compatred to e.g.
primates), prominent structure at
the cranial end of the mouse brain. The olfactory bulb
borders caudally with the cerebral
cortex and is the only main sensory complex which
transduces information directly to the
cerebrum, bypassing the thalamus. Olfactory input is
critical for numerous actions, e.g.
identification of other mice and mediation of emotional
responses, reproductive and maternal
behavior, detection of predators and food selection.
Rest Brain
The rest brain comprises several distinct anatomical regions, namely the nucleus accumbens, the ventral striatum, the caudate putamen and the basal forebrain. It is located ventral of the cerebral cortex and forms the base of the mouse brain, bordering rostral to the olfactory bulb and caudal to the thalamus respectively hypothalamus. Functionally, it integrates the input of telencephalic and non-telencephalic regions of the brain and plays a role in a multitude of processes such as motor control, sensorimotor behavior and habit formation. In humans, this region and its afferent structures are also associated with a number of distinct neurodegenerative diseases, such Parkinson’s and Huntington’s disease. Furthermore, specifically the nucleus accumbens is part of the dopaminergic reward system and involved in many addictive behavioral disorders.
Hypothalamus
The hypothalamus controls important high-level physiological
processes such as blood
pressure, body temperature, breathing, circadian rhythm,
food intake and digestion and
reproduction. It regulates the endocrine and
cardiovascular system, releasing several
neuroendocrine hormones and is also closely associated
with glands like the pituitary and
thyroid gland. The Hypothalamus is located at the bottom
surface of the brain lying on the
skull base, ventral of the thalamus.
Thalamus
The thalamus mediates almost all sensory and motor signals
and relays them to the cerebral
cortex. Information input occurs from the brainstem,
spinal cord, cerebellum, amygdala and
the caudate putamen. A key exception is the olfactory
sense, which bypasses the thalamus. It
is a structure of gray matter located deep inside the
brain dorsal of the hypothalamus,
bordering the Cerebrum cranially and the midbrain
caudally.
Hypophysis
The
Hypophysis (also known as pituitary gland) is a small sized endocrine gland located in a bony cavity called the sella
turcica, part of the sphenoid
bone of the mouse skull directly beneath the hypothalamus, to which it is connected by a slender stalk called the infundibulum.
It is composed of two lobes of different embryonic origin and function, the anterior lobe or adenohypophysis and the posterior lobe or neurohypophysis. The anterior pituitary contains various hormone-secreting cells responsible for producing and releasing
several key hormones (e.g. growth hormone (GH), thyroid-stimulating hormone (TSH), follicle-stimulating hormone (FSH) and luteinizing hormone (LH)). The posterior pituitary does not produce hormones itself but stores and releases hormones like oxytocin and
vasopressin (antidiuretic hormone, ADH) that are synthesized in the hypothalamus.
The mouse pituitary gland, often referred to as the "master gland" of the endocrine system, is itself regulated by neurosecretory neurons located in the hypothalamus (hypothalamic-pituitary axis) and a feedback mechanism from circulating hormonal signaling originating
from various target tissues. As a central hub in the endocrine system, the pituitary gland plays a crucial role in regulating growth, metabolism, stress responses, reproduction, and fluid balance. Disruptions in its function—whether due to altered hormonal
pathways or tumor growth—can lead to a range of diseases, including hypopituitarism, acromegaly, Cushing’s disease, and diabetes insipidus.
Midbrain
The midbrain is the most cranial part of the mouse brainstem.
It continues caudally with the
pons and borders cranially with thalamus, hypothalamus
and parts of cerebrocortical mantle.
The midbrain houses importand dopaminergic neuron
populations in its ventral region which
play a significant role in motor control. Furthermore,
the midbrain controls extra- and
intraocular eye muscles via the oculomotor and trochlear
nerves.
Cerebellum
The cerebellum is an important structure for the control and
learning of motor actions but
plays also a port in regulating arousal, emotion and
cognition. The cerebellum is the most
dorsal part of the brainstem, composed of white and gray
matter and located at the
dorsocaudal end of the brain. Unlike the smooth
cerebrum, the cerebellum can be easily
identified by the transverse sulci on its surface.
Pons
The Pons is a direct continuation of the medulla and borders
dorsally with the cerebellum and
rostrally with the midbrain. It houses several nuclei of
important nerves involved in e.g.
the sense of equilibrium, hearing and the control of the
jaw and fascial muscles.
Furthermore, it is the anatomical connection of the
cerebullum with the spinal cord and the
rest of the mouse brain.
Medulla
The Medulla is located at the caudal end of the mouse brain
and forms ist connection with the
spinal cord. In contrast to the spinal cord, it is
endowed with nuclei of nerves for the
innervation of various craniofascial structures such as
the tongue, the muscles of the
pharynx and larynx and additionally some neck muscles.
Choroid Plexus
The choroid plexus is a cluster of branching epithelial
networks covering a capillary
scaffold located in each of the four brain ventricles.
It houses a specialized, non-neuronal
cell population whose function is to synthesize and
secrete the cerebrospinal fluid.
Structurally, it functions also as a blood-brain barrier
and is involved in the removal of
toxins and metabolic waste products from the central
nervous system. Furthermore, it has a
role in regulating neurogenesis and inflammation.
Cerebral Cortex
The cortex is the hierarchically highest part of the central
nervous system in terms of
information processing. It receives and integrates all
sensory information and is
responsible for voluntary action. The cerebral cortex is
a large, mantle-like structure
consisting of gray matter and covering deeply located
parts of the brain like hippocampus,
thalamus, hypothalamus and lateral parts of the
midbrain. Unlike in larger mammals, e.g.
primates, the mouse cortex is smooth and does not
display sulci or gyri. On the surface, it
borders the olfactory bulb rostrally and the cerebellum
caudally. Functionally, the cerebral
cortex is organized in a topic fashion, i.e. defined
cortical regions represent certain
regions of the body.