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MRCPsych Part A > Neuroanatomy > Flashcards

Flashcards in Neuroanatomy Deck (262)
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1
Q

What is the cerebrum divided into?

A

Frontal lobe
Temporal lobe
Parietal Lobe
Occipital Lobe

2
Q

What are sulci and gyri?

A

Sulci: valleys
Gyri: ridges
The heavy foldings of the lobar surfaces

3
Q

What are the primary (major) sulci?

A

More invariant in appearance than secondary sulci

4
Q

What is the central sulcus?

A

Divides frontal lobe from parietal lobe?

5
Q

What divides frontal lobe from parietal lobe?

A

Central sulcus

6
Q

Where is the precentral gyrus?

A

Frontal lobe

7
Q

Where is the primary motor cortex?

A

Precentral gyrus

8
Q

Where is the motor homunculus?

A

Primary motor cortex

9
Q

Where is the postcentral gyrus?

A

Parietal lobe

10
Q

What is the postcentral gyrus?

A

Primary somatosensory cortex

11
Q

Where is the sensory homunculus?

A

Primary somatosensory cortex

12
Q

What is the Sylvian fissure?

A

Lateral sulcus

13
Q

What divides the frontal lobe from the temporal?

A

Lateral sulcus

14
Q

What does the Sylvian fissure do?

A

Divides frontal lobe from temporal.

15
Q

What is the fifth lobe of the cerebrum?

A

Insula

16
Q

Where is in the insula?

A

Deep in Sylvian fissure

17
Q

What is the insula?

A

Seat of the primary gustatory cortex

18
Q

Where is the middle frontal gyrus?

A

Between the superior and inferior frontal sulci

19
Q

What is in the middle frontal gyrus?

A

Dorsolateral prefrontal cortex

20
Q

What does the dorsolateral prefrontal cortex do?

A

Executive functions

21
Q

Where is the cingulate sulcus?

A

Medial side of frontal lobe

22
Q

Where is the seat of motivation?

A

Anterior position of adjoining cingulate gyrus

23
Q

Which sulci are on the inferior surface of frontal lobe?

A

Olfactory and orbital sulci

24
Q

What does the orbitofrontal cortex do?

A

Seat of associative learning and decision-making

25
Q

What does the superior temporal sulcus do?

A

Primary auditory cortex

26
Q

What separates the superior and inferior parietal lobes?

A

Superior temporal sulcus

27
Q

What does the superior temporal sulcus do?

A

Seat of primary auditory cortex

28
Q

What part of the cortex is involved in executive functions?

A

Dorsolateral prefrontal cortex

29
Q

Where does decision-making and associative learning occur?

A

Orbitofrontal cortex

30
Q

What is the inferior parietal lobe made of?

A

Angular gyrus

Supramarginal gyrus

31
Q

What is the inferior parietal lobe important for?

A

Visuospatial attention

32
Q

Where does visuospatial attention occur?

A

Inferior parietal lobe

33
Q

Where is the primary visual cortex?

A

Calcarine sulcus in medial occiptal cortex

34
Q

What is the sulcus in the medial occipital cortex?

A

Calcarine sulcus

35
Q

What happens to higher level of associative functions in the hemispheres?

A

Lateralize to one or other hemisphere

36
Q

Where is language comprehension?

A

Localized to left temporal corte

37
Q

What is prosody?

A

Tonal modulation of speech

38
Q

Where is prosody located?

A

Right hemisphere

39
Q

Where is the dominant hemisphere?

A

Contralateral to dominant hant

40
Q

What does the dominant hemisphere do?

A

Mediates language and speech functions

41
Q

How can dominance be tested?

A

Annette’s handedness scale

Edinburgh handedness inventory

42
Q

How many right-handed people have a dominant right hemisphere?

A

10%

43
Q

How many left-handed people have a right dominant hemisphere?

A

20%

44
Q

How many left handed people have left dominant hemisphere?

A

64%

45
Q

How many left handed people have bilateral dominance?

A

16%

46
Q

Where is the planum temporale?

A

Upper surface of superior temporal gyrus

Larger on left in 65% of people

47
Q

What is the planum temporale?

A

Triangular region, important for language processing.

48
Q

What is the most asymmetrical structure in the human brain?

A

Planum temporale

49
Q

Which asymmetry is reduced or reversed in schizophrenia?

A

Plaum temporale

50
Q

Signs in left hemisphere lesions

A
Aphasia
Right-left disorientation
Finger agnosia
Dysgraphia (aphasic)
Dyscaculia (number alexia)
Limb aprexia
51
Q

Signs in right hemisphere lesions

A
Visuospatial deficits
Anosognosia
Neglect
Dysgraphia (spatial, neglect)
Dyscalculia (spatial)
Constructional apraxia
Dressing apraxia
52
Q

Which hemisphere lesion leads to face recognition?

A

Bilateral

53
Q

What are the subcortical structures?

A
Limbic system
Medial Temporal structures
Basal ganglia
Thalamus
Hypothalamus
54
Q

Who first described the limbic lobe?

A

Broca

55
Q

Who first assigned the function of emotional processing to limbic structures?

A

Papez, then Maclean

56
Q

What is the Papez circuit of the limbic system?

A
Hippocampus
Fornix
Mamillary bodies
Mammillothalamic tract
Anterior thalamic nucleus
Genu of internal capsule
Cingulate gyrus
Parahippocampal gyrus
Entorhinal cortex
Perforant pathway
Back to hippocampus
57
Q

What are the boundaries of the limbic system post-Papez?

A

Include amygdala, septum, basal forebrain, nucleus accumbens, orbitofrontal cortex

58
Q

Functions of limbic system?

A

Mediation of emotional responses via amygdala
Influencing neuroendocrine responses via hypothalamus
Reward system regulation via nucleus accumbens

59
Q

Function of nucleus accumbens?

A

Reward system

60
Q

Function of hypothalamus?

A

Neuroendocrine response

61
Q

Function of amygdala?

A

Mediation of emotional repsonses
Fear conditioning
Emotional regulation

62
Q

What are the medial temporal structures?

A

Hippocampus
Amygdala
Entorhinal and parahippocampal cortex

63
Q

Function of hippocampus?

A

Memory processes

Continuous production of new neurons in adult life

64
Q

What is the basal ganglia?

A

Group of gray matter nuclei

65
Q

What is the largest subcortical structure?

A

Basal ganglia

66
Q

Function of basal ganglia?

A

Planning and programming of movement

Concerting abstract thought into voluntary action

67
Q

What is in the basal ganglia?

A

Striatum: caudate nucleus + putamen
Pallidum: globus pallidus

68
Q

What are the lentiform nucleus?

A

Putamen and globus pallidus

69
Q

What is the striatum in basal ganglia made up of?

A

Caudate nucleus

Putamen

70
Q

What structures are functionally related to basal ganglia but not part of structure?

A

Substantia nigra

Subthalamic nuclei

71
Q

Where does basal ganglia receive input from?

A

Glutamatergic corticostriatal projection

72
Q

Who described the circuits in the basal ganglia?

A

Alexander

73
Q

What are the important circuits in the basal ganglia?

A
Motor
Oculomotor
Dorsolateral prefrontal (executive)
Anterior cingulate (motivation)
Lateral orbitofrontal (social intelligence)
74
Q

Which circuit in the basal ganglia is for social functioning?

A

Lateral orbitofrontal circuit

75
Q

Which circuit in the basal ganglia is for motivation?

A

Anterior cingulate

76
Q

Which circuit in the basal ganglia is for executive?

A

Dorsolateral prefrontal circuit

77
Q

Disorders involving basal ganglia dysfunction

A
OCD
Tourette's
Huntington's chorea
Wilson's disease
CO poisoning
Hemiballismus
Parkinsonism
Fahr's disease
78
Q

What basal ganglia dysfunction causes OCD?

A

Volumetric changes + higher blood flow to caudate nuclei.

Increased caudate metabolism reduces after effective treatment.

79
Q

What is he basal ganglia dysfunction in Tourette’s?

A

Striatal dopaminergic dysfunction

80
Q

What is the basal ganglia dysfunction in Huntington’s chorea?

A

Degeneration of striatum - mainly caudate nucleus - and selective loss of GABAergic neurons

81
Q

What is the basal ganglia dysfunction in Wilson’s disease?

A

Copper deposits in lenticular nuclei

82
Q

What is the basal ganglia dysfunction in CO poisoning?

A

Acute bilateral anoxic damage to basal ganglia

83
Q

What is the basal ganglia dysfunction in hemiballismus?

A

Subthamalic nucleus damage - especially infarction

84
Q

What is the basal ganglia dysfunction in Parkinsonism?

A

Depigmentation of substantia nigra - Lewy bodies seen.

Striatal overactivity associated with bradykinesia

85
Q

What basal ganglia dysfunction is linked with bradykinesia in Parkinsonism?

A

Striatal overactivity

86
Q

What basal ganglia dysfunction is linked to Fahr’s diease?

A

Progressive calcium deposition in basal ganglia.

87
Q

What is the thalamus?

A

Oval mass of grey matter nuclei in subcortial region.

88
Q

What does the thalamus do?

A

Relays all types of sensory information except olfaction onto cortex.
Filter sensory information in preparation for cortical processing.
Relays cerebellar and basal ganglia inputs to cerebral cortex.

89
Q

Structure of anterior thalamus

A

Receives mamillothalami tract and fornix

Connects to cingulate cortex

90
Q

What does anterior thalamus do?

A

Relays information from hypothalamus and hippocampus onto frontal cortex

91
Q

What in the thalamus is associated with visual attention?

A

Pulvinar

92
Q

Where are sleep spindles in the thalamus?

A

Generated in reticular nucleus

93
Q

Function of hypothalamus

A

Regulates physiological functions - eating, drinking, sleeping, temperature regulation
Neuroendocrine role

94
Q

What is the ventromedial hypothalamus?

A

Satiety centre

95
Q

Where is the satiety centre?

A

Ventromedial hypothalamus

96
Q

Where is the feeding centre?

A

Lateral hypothalamus

97
Q

What type of lesion leads to obesity in animals?

A

Lesion in ventromedial hypothalamus hyperphagia

98
Q

Where is the inferior olivary nucleus?

A

Brainstem

99
Q

What does the inferior olivary nucleus do?

A

Aids in motor coordination by projecting climbing fibres to contralateral cerebellar cortex via inferior cerebellar peduncle

100
Q

Signs in inferior olivary nucleus lesions

A

Appendicular ataxia due to motor incoordination of contralateral arm and leg
Fail finger-nose test

101
Q

Role of cerebellum

A

Preparing motor plan
Predicting balance needed between muscle groups to carry out action
Cognitive processes

102
Q

Signs of cerebellar lesions

A
Ataxia
Coarse intentional tremors
Hypotonia
Past pointing
Pendular knee jerk
103
Q

Function of cerebellum in schizophrenia

A

Disrupted cortico-cerebellar circuity can lead to cognitve dysmetria - difficulty in coordinating and monitoring process of receiving, processing and expressing information.

104
Q

What is the brainstem made up on?

A

Midbrain
Pons
Medulla

105
Q

What is the midbrain made up of?

A

Superior and inferior colliculi
Substantia nigra
Periaqueductal grey matter

106
Q

What do the superior and inferior colliculi do?

A

Superior - conjugate gaze control

Inferior - auditory source localization

107
Q

What does the periaqueductal grey matter do?

A

Vocalization

Freezing response to threat and pain

108
Q

Where is the pons?

A

Beneath cerebeullum

Surrounds upper helf of 4th centricle

109
Q

Where is the medulla?

A

Inferior part of 4th ventricle

Continuous with spinal cord

110
Q

Which part of the brainstem is continuous with the spinal cord?

A

Medulla

111
Q

Anatomical feature of Olfactory nerve

A

Runs on basal surface of frontal cortex w/o passing through thalamus.
Formed as outgrowth of forebrain.

112
Q

Anatomy of optic nerve

A

Outgrowth of forebrain.

Relays via thalamus - geniculate body.

113
Q

Anatomy of oculomotor nerve.

A

Motor function.

Supplies 4/6 of ocular muscles.

114
Q

Anatomy of trochlear nerve.

A

Motor function

Supplies superior oblique.

115
Q

Anatomy of trigeminal nerve

A

Sensory + motor.
Transmits facial sensation
Controls jaw muscles

116
Q

Anatomy of abducens nerve

A

Motor.

Supplies lateral abducens.

117
Q

Anatomy of facial nerve.

A

Sensory + motor.
Transmits taste sensation
Controls facial muscles.

118
Q

Anatomy of vestibular nerve.

A

Transmits auditory sensation.

119
Q

Anatomy of cochlear nerve

A

Transmits balance sesnation

120
Q

Anatomy of glossopharyngeal nerve

A

Motor control of pharynx
Parasympathetic control of parotid gland
Taste from back of tongue

121
Q

Anatomy of vagus nerve

A

Motor control of larynx and pharynx.
Parasympathetic control of viscera.
Visceral sensations.

122
Q

Anatomy of accessory nerve.

A

Motor control of neck muscles.

123
Q

Anatomy of hypoglossal

A

Motor control of tongue muscles

124
Q

Where is grey matter in the cerebrum?

A

Outer surface

125
Q

Where is grey matter in the spinal cord?

A

Inner surface

126
Q

What does the white matter form in the spinal cord?

A

Anterior, lateral and dorsal columns

127
Q

What does the dorsal column of the spinal cord carry?

A

Proprioceptive sensory fibres

128
Q

What is the spinothalamic tract made of?

A

Anterior and lateral columns

129
Q

What information does the spinothalamic tract carry?

A

Touch
Pressure
Pain
Temperature

130
Q

What secretes CSF?

A

Choroid plexus in lateral, third and fourth ventricles

131
Q

Rate at which CSf is produced

A

300ml/day

132
Q

Route of CSF

A
Secreted from choroid plexus
From lateral ventricle to interventricular foramina of Monroe
Into 3rd ventricle
Into Aqueduct of Sylvius
4th ventricle
Foramen of Magendie (single)
and Foramina of Luschka (two lateral)
Subarachnoid space
133
Q

How does CSF go from lateral to 3rd ventricle?

A

Interventricular formina of Monroe

134
Q

How does CSF go from 3rd to 4th ventricle?

A

Cerebral aqueduct of Sylvius

135
Q

How does CSF go from 4th ventricle to subarachnoid space?

A

Foramen of Magendie (single) and

Foramina of Luschka (two lateral)

136
Q

Where is the body of the lateral ventricle?

A

Below corpus callosum

137
Q

What separates the two lateral ventricles?

A

Septum pellucidum

138
Q

Where is the third ventricle?

A

Between thalamus and hpothalamus

139
Q

Where is the fourth ventricle?

A

Above pons

Below cerebellum

140
Q

Where does obstruction to CSF commonly occur?

A

3rd or 4th ventricle (Foraman of Monroe)

141
Q

What happens in communicating hypocephalus?

A

Impairment of CSF reabsorption in subarachnoid space due to partial occlusion of arachnoid villi

142
Q

What does the internal carotid artery divide into?

A

Anterior cerebral and middle cerebral artery

143
Q

What does anterior cerebral artery supply?

A

Medial and superior strip of lateral aspect of cerebral cortex up to parietal/occipital border

144
Q

What does the middle cerebral artery supply?

A

Lateral aspect of cerebral cortex, including Brocas and Wernickes in dominant hemispheres

145
Q

Which artery supplies Brocas and Wernickes?

A

Middle cerebral artery

146
Q

What does the posterior cerebral artery supply?

A

Inferomedial temporal lobe

Occipital lobe

147
Q

Which artery supplies the occipital lobe?

A

Posterior cerebral artery

148
Q

Where does the posterior cerebral artery arise from?

A

Basilar artery

149
Q

What supplies the medulla?

A

Posterior inferior cerebellar arteries

Anterior spinal branches of vertebral arteries

150
Q

What supplies the pons?

A

Basilar artery

151
Q

Signs of carotid system TIA

A
Amaurosis fugax
Aphasia
Hemiparesis
Hemisensory loss
Hemianopic visual loss
152
Q

What causes amaurosis fugax?

A

Blockade of retinal arteries

153
Q

Signs of vertebrobasilar TIA

A
Diplopia, vertigo, vomiting
Choking, dysarthria
Ataxia
Ataxia without agraphia
Hemisensory loss
Hemianopic visual loss
Transient global amnesia
Tetraparesis
LOC
154
Q

What supplies the premotor cortex?

A

Anterior cerebral artery

155
Q

What supplies the cingulum?

A

Anterior cerebral artery

156
Q

Bilateral infarct of anterior cerebral artery results in which signs

A
Quadriparesis (legs weaker than arms)
Akinetic mutism (ventromedial or cingulate syndrome)
157
Q

What supplies the caudate nucleus?

A

Recurrent artery of Huebner (branch of anterior cerebral artery)

158
Q

Lesion effect of caudate nucleus

A

Initially agitated, confused

Evolves to akinesia, abulia with mutism and personality changes

159
Q

What supplies the lateral prefrontal cortex?

A

Anterior branches of upper division of middle cerebral artery

160
Q

Signs of lesion of lateral prefrontal cortex

A

Planning deficits
Impairment of working memory
Apathy

161
Q

What supplies the basal forebrain?

A

Anterior comunicating artery

162
Q

Signs of lesion in basal forebrain

A

Akinesia
Personality change - orbitofrontal dysfunction
Confabulatory amnesia

163
Q

What supplies the lateral medulla?

A

Posterior inferior cerebellar artey

164
Q

Lesion effect of lateral medulla or of thrombus in PICA?

A

Wallenberg’s lateral medullary syndrome.
Acute vertigo with cerebellar signs.
Ipsilateral face numbness, diplopia, nystagmus
Horners syndrome
IX/X nerve palsy with contralateral spinothalamic sensory loss and mild hemiparesis

165
Q

When does Wallenberg’s lateral medullary syndrome occur?

A

Thrombus in PICA

Lesion in lateral medulla

166
Q

Types of white matter pathways

A

Projection fibres
Association fibres
Commissural fibres

167
Q

What are projection fibres?

A

Run vertically, connecting higher and lower centres of the brain

168
Q

What are association fibres?

A

Interconnect different regions within same hemisphere of brain

169
Q

What are commissural fibres?

A

Interconnect similar regions in opposite hemisphere.

170
Q

What does the anterior commissure do?

A

Interconnects olfactory bulbs

171
Q

What does the posterior commissure do?

A

Interconnects midbrain pretectal nuclei

172
Q

What interconnects the posterior dorsal thalamic nuclei?

A

Hippocampal commissure

Habenular commissure

173
Q

What supplies anterior aspect and most of the body of the corpus callosum?

A

Pericallosal artery (from anterior cerebral artery)

174
Q

Signs of vascular disruption to pericallosal artery?

A

Left sided apraxia and agnosia

175
Q

What is the posterior aspect of the corpus callosum called?

A

Splenium

176
Q

What supplies the splenium?

A

Posterior cerebral artery

177
Q

Signs of vascular disruption to splenium?

A

Alexia and color anomia

Preserved ability to copy words

178
Q

Why is there preserved ability to copy words but not color in disruption of vasularity to splenium?

A

Motor information can be relayed via anterior corpus callosum instead

179
Q

What is the fornix?

A

Connects hippocampus to hypothalamus via mamillary bodies

180
Q

Is fornix white or grey matter?

A

White

181
Q

Function of fornix

A

Relays cortical input to regulate neuroendocrine and autonomic systems

182
Q

What connects Brocas and Wernickes?

A

Arcuate fasciculus

183
Q

What does damage to Arcuate fasciculus result in?

A

Conduction aphasia

184
Q

What is the uncinate fasciculus?

A

Connects orbitofrontal cortex to anterior temporal lobs.

185
Q

Function of unicate funculus?

A

Social cognition

Language

186
Q

Who divided the cortical layers into 47 specialised areas?

A

Brodmann

187
Q

What is the neocortex made up of as per Brodmann?

A

6 Layers

188
Q

Which layers in the neocortex are mainly afferent?

A

Layers 2 and 4

189
Q

Which layers in the neocortex are mainly efferent?

A

Layers 5 and 6

190
Q

What makes up cortical neurons?

A

75% is pyramidal neurons

25% are stellate cells - not in layer 1

191
Q

What is Layer 1?

A

Molecular/agranular

192
Q

Cells in Layer 1?

A

Glial cells
Dendrites from neurons of deeper layers
Horizontal cells of Cajal

193
Q

Name of Layer 2?

A

External Granular layer

194
Q

Cells in Layer 2

A

Granule cells

Small pyramidal cells (larger as you go down layers)

195
Q

Name of Layer 3?

A

External pyramidal layer

196
Q

Cells in layer 3?

A

Small and medium sized pyramidal cells

197
Q

Name of layer 4?

A

Internal granular layer

198
Q

Cells in layer 4?

A

Some pyramidal cells
Mostly granule cells
Receives thalamocortical inputs

199
Q

Name of layer 5?

A

Internal pyramidal layer

200
Q

Cells in layer 5?

A

Largest pyramidal cells - particularly motor cortex - betz cells

201
Q

Name of layer 6?

A

Multiform layer

202
Q

Cells in layer 6?

A

All cells
Spindle cells
Martinotti cells
Major source of corticothalamic fibres

203
Q

Which layer gives rise to association/commissural and projection fibres?

A

Layer 6

204
Q

How is the cerebelar cortex described as per Brodmann?

A

Three layered
Molecular - basket and stellate cells
Purkinje - Purkinje cells
Granular - granule and golgi cells

205
Q

What are Purkinje cells?

A

Class of GABAergic neurons in cerebellar cortex only.

Connect to deep cerebellar nuclei via inhibitory projections.

206
Q

Function of purkinje cells?

A

For sole output of all motor coordination in cerebellum.

207
Q

Where are granule cells?

A

Granular layer of cerebeullum
Layer 4 of cerebral cortex
Denate gyrus of hippocampus
Olfactory bulb

208
Q

Where are Betz cells?

A

Primary motor cortex - fifth layer of grey matter.

209
Q

What are Betz cells?

A

Pyramidal cell neurons - largest in CNS.

10% of total pyramidal cell population in layer 5 of primary motor cortex.

210
Q

Where are stella cells?

A

Layer 4 of cerebral cortex (from thalamus forward to pyramidal cells)
Cerebeullum

211
Q

What do glial cells do?

A

Supportive metabolic functions

Modulate neuronal functions via neurosteroids

212
Q

Types of glial cells

A

Astrocytes
Oligodendrocytes
Microglia
Ependymal cells

213
Q

Which glial cell is most predominant?

A

Astrocyte

214
Q

What are astrocytes?

A

Enable nutrition of neurons
Breakdown of neurotransmitters
Maintain blood-brain barrier

215
Q

Where are oligodendrocytes?

A

CNS

216
Q

What do oligodendrocytes do?

A

Produce myelin sheaths

217
Q

What do microglia do?

A

Scavenger cells that clear neuronal debris following cell death

218
Q

What do ependymal cells do?

A

Cover ventricles and facilitate csf circulation via their ciliary processes.

219
Q

Where is the blood brain barrier located?

A

In endothelial cells of capillaries in the brain.

220
Q

How do endothelial cells in brain capillaries form the blood-brain barrier?

A

Tight junctions with high electrical resistance as barrier against molecules.

221
Q

How are blood capillaries separated from neurons?

A

Brain capillaries are in contact with foot processes of astrocytes

222
Q

What molecules can go through blood-brain barrier?

A

Lipid soluble (ethanol and caffeine) via lipid membrane of cells

223
Q

What olecues cannot go through blood brain barrier?

A

Water-soluble molecules such as Na and K.

224
Q

What is the name of the brain which does not have a blood brain barrier?

A

Circumventricular organs

225
Q

Examples of circum-ventricular organs

A

Subfornical organ
Area postrema (chemoreceptor trigger zone)
Median eminence
Posterior pituitary

226
Q

Classification of dopaminergic pathways

A

Long
Short
Ultrashort

227
Q

Long dopaminergic pathways

A

Nigrostriatal
Mesocortical
Mesolimbic

228
Q

Short dopaminergic pathways

A

Tuberoinfundibular

Incertohypothalamic

229
Q

Ultrashort dopaminergic pathways

A

In amacrine cells in retina and olfactory system

230
Q

Which dopaminergic pathway is the extrapyramidal pathway?

A

Nigrostriatal - crucial for motor control

231
Q

Origin and destination of nigrostriatal pathway

A

Substantia nigra to striatum and amygdala via medial forebrain bundle

232
Q

Effect of dopamine blockage in nigrostriatal pathway?

A

Dopamine deficiency - Parkinsons

Blockade due to antipsychotics can cause extrapyramidal SEs

233
Q

Origin and destination of mesolimbic pathway?

A

Ventral tegmental area to nucleus accumbens and hippocampus via medial forebrain bundle

234
Q

Effect of dopamine blockade on nmesolimbic pathway?

A

Produces desirable antipsychotic effect by controlling positive psychotic symptoms

235
Q

Origin and destination of mesocortical pathway?

A

Ventral tegmental area to cingulate cortex and prefrontal regions via medial forebrain bundle

236
Q

Effect of dopamine blockade on mesocortical pathway?

A

Low levels of dopamine in this pathway lead to negative symptoms - alogia, anhedonia, amotivation, apathy

237
Q

Origin and destination of tuberoinfundibular pathway?

A

Hypothalamus to pituitary via portal vessels

238
Q

Effect of dopamine blockade on tuberoinfundibular pathway?

A

Dopamine acts as prolactin inhibitory hormone. Thus, low dopamine levels will increase prolactin.

239
Q

Origin and destination of incertohypothalamic pathway?

A

Internal connections within hypothalamus

240
Q

Effect of dopamine blockage within incertohypothalamic pathway?

A

Disturbed thermoregulation and weight gain

241
Q

What are the cholinergic pathways?

A

Brainstem

Basal forebrain

242
Q

What is the brainstem cholinergic pathway?

A

Forms part of ascending reticular activating system.

243
Q

Function of brainstem cholinergic pathway?

A

Maintains wakefulness and REM sleep.

244
Q

Origination of brainstem cholinergic pathway?

A

Originates from pedunculopontine and laterdorsal tegmental nuclei.

245
Q

What does brainstem cholinergic pathway innervate?

A

Thalamic relay neurons

Reticular nuclei

246
Q

Where does basal forebrain cholinergic pathway originate and project to?

A

Originates in nucleus basalis of meynert in basal forebrain

Projects to hippocampus, frontal cortex and amygdala

247
Q

What does degeneration of basal forebrain cholinergic pathway result in?

A

Alzheimer’s disease

248
Q

Where do most serotonergic neurons originate and ascend to?

A

Midbrain dorsal and median raphe nuclei
Ascend to innervate entire cortex, basal ganglia, thalamus
Descend to spinal cord

249
Q

Where do noradrenergic pathways priginate and ascend to?

A

Originate in loculs coeruleus (pons)
Ascend to cortex via medial forebrain bundle
Descend to spinal cord

250
Q

Most common excitatory neurotransmitter in brain?

A

GLutamate

251
Q

What makes up most of the corona radiata?

A

Cortiofugal fibres

252
Q

Which tracts are predominantly glutamatergic?

A
Almost all cortical descending tracts
Corticofugal fibres - corona radiata
All association and commissural fibres
Thalamocorticol
Cerebellar output from deep nuclei, subthalamic nuclei to globus pallidus projections 
Brainstem to spinal cord
253
Q

What is the primary inhibitory neurotransmitter?

A

GABA

254
Q

What is the major transmitter for cerebral interneurons?

A

GABA

255
Q

Name two major cortical interneuron subtypes

A

Parvalbumin-expressing interneurons (40%)

Somatostatin-expressing interneurons (30%) - Martinotti cells

256
Q

What can reduction in expression of parvalbumin-expressing interneurons lead to?

A

Schizophrenia

257
Q

Subtypes of parvalbumin-expressing interneurons?

A

Basket cells

Chandelier cells

258
Q

What are basket cells?

A

Receive direct input from thalamocortical projections.

Form synapses with soma or dendrites of pyramidal neurons

259
Q

Function of basket cells

A

Provide excitatory-inhibitory balance to cortex

260
Q

What are chandelier cells?

A

Form synapses with proximal axonal hillock of pyramidal neurons.

261
Q

Function of chandelier cells?

A

Overall excitatory role by serving to short-circuit the action potential propagation

262
Q

Which artery supplies the dorsolateral prefrontal circuit?

A

MCA