Lecture 4: The Ventral Hippocampus
Two superficially incompatible/competing hypotheses about the role of the hippocampus. Can
these two competing roles be resolved?
The vast majority of recent research has implicated Hpp in spatial navigation and memory
(cognitive/spatial map)
Two classic theories of hippocampal function:
• Cold hippocampus Commented [IM66]: Calmly predicts your position in space and
how to get from one place to another without getting emotionally
o Spatial navigation and memory involved
• Hot hippocampus Commented [IM67]: Not really involved in space or navigation
o Emotional processing and memory at all
Evidence that hippocampus is intimately involved in brains
How can these two theories be reconciled/ co-exist? emotional responses
Evidence for a dorsal-ventral dichotomy
Evidence via anatomy, function & neurophysiology of d/v hippocmapus
Evidence for a functional dissociation between dorsal and ventral hippocampus
Is the hippocampus more than spatial?
Vast majority of research suggest hippocampus to be involved in correct spatial navigation,
particularly in humans
• In humans, alterations in Hpp are associated with memory and spatial cognition
o Lesions, activity during navigation tasks (fMRI)
• But also suggestions of hippocampal involvement in other roles:
o Stress response (Acute and chronic)
o Chronic stress and long term effects
o Depression
§ Reduction in size of hippocampus —> only consistent alteration in brain that
correlates with onset and severity of depressive symptoms
o GAD
o Phobias [snakes, ref à large hippocampal activation]
o Addiction
o Altered goal-directed behaviour and decision making; the anticipation of
upcoming rewards
• Many potential roles for the Hpp unrelated to spatial navigation/learning
o Some of these aspects could be associated with space (e.g. anxiety or depression at
particular locations, navigation towards role) but strong suggestion of
independence from spatial role, due to large amount of evidence for non-spatial
potential roles
, The non-spatial argument of hippocampal function
In rodents, lesions/inactivations in hippocampus results in dramatic loss in ability to use spatial cues
to solve a task
In rodents, hippocampus contains place cells (encode position), head-direction cells (encode
direction facing), and boundary-vector cells and grid cells in extended hippocampal system
Both classic and recent research has also implicated the hippocampus in emotional (so-called
‘hot’) behaviours as well.
• Rodents with altered hippocampal function (lesions) results in altered spatial navigation and
memory
• BUT ALSO:
o Impaired response to threatening situations
o Withdrawals and impaired social interaction
o Impaired goal-directed behaviour
o Change in the level of anxiety
o Altered stress response (hormones, blood pressure) (change levels of stress
hormones in blood)
• Evidence suggests these roles can be independent of spatial processing, though one could
argue navigation links
(Kluver & Bucy, 1939) - Hpp lesions in monkeys —> aggressive, emotional and sexual deviation;
profound effects on emotional behaviour
There is much evidence across species for both hot and cold hippocampus
Can these two viewpoints be resolved?
Gross Anatomy of Hippocampus
• The circuit is the same throughout entire length (ventral - dorsal); tri-synaptic loop
o But does the whole length do the same thing?
• Brain classically split into evolutionary ancient emotional ventral structures (hot) and
cognitive (cold) dorsal structures; ventral = hot, emotional; dorsal = cold, cognitive
• Most studies that say the hippocampus is purely spatial almost entirely focus on dorsal
structures
o Many studies that say hippocampus is emotional tend to focus on ventral
§ Could be coincidence?
Are dorsal (cold) and ventral (hot) hippocampus actually different structures with different roles?
Dorsal-Ventral Dichotomy?
(Strange et al. 2014)
Two superficially incompatible/competing hypotheses about the role of the hippocampus. Can
these two competing roles be resolved?
The vast majority of recent research has implicated Hpp in spatial navigation and memory
(cognitive/spatial map)
Two classic theories of hippocampal function:
• Cold hippocampus Commented [IM66]: Calmly predicts your position in space and
how to get from one place to another without getting emotionally
o Spatial navigation and memory involved
• Hot hippocampus Commented [IM67]: Not really involved in space or navigation
o Emotional processing and memory at all
Evidence that hippocampus is intimately involved in brains
How can these two theories be reconciled/ co-exist? emotional responses
Evidence for a dorsal-ventral dichotomy
Evidence via anatomy, function & neurophysiology of d/v hippocmapus
Evidence for a functional dissociation between dorsal and ventral hippocampus
Is the hippocampus more than spatial?
Vast majority of research suggest hippocampus to be involved in correct spatial navigation,
particularly in humans
• In humans, alterations in Hpp are associated with memory and spatial cognition
o Lesions, activity during navigation tasks (fMRI)
• But also suggestions of hippocampal involvement in other roles:
o Stress response (Acute and chronic)
o Chronic stress and long term effects
o Depression
§ Reduction in size of hippocampus —> only consistent alteration in brain that
correlates with onset and severity of depressive symptoms
o GAD
o Phobias [snakes, ref à large hippocampal activation]
o Addiction
o Altered goal-directed behaviour and decision making; the anticipation of
upcoming rewards
• Many potential roles for the Hpp unrelated to spatial navigation/learning
o Some of these aspects could be associated with space (e.g. anxiety or depression at
particular locations, navigation towards role) but strong suggestion of
independence from spatial role, due to large amount of evidence for non-spatial
potential roles
, The non-spatial argument of hippocampal function
In rodents, lesions/inactivations in hippocampus results in dramatic loss in ability to use spatial cues
to solve a task
In rodents, hippocampus contains place cells (encode position), head-direction cells (encode
direction facing), and boundary-vector cells and grid cells in extended hippocampal system
Both classic and recent research has also implicated the hippocampus in emotional (so-called
‘hot’) behaviours as well.
• Rodents with altered hippocampal function (lesions) results in altered spatial navigation and
memory
• BUT ALSO:
o Impaired response to threatening situations
o Withdrawals and impaired social interaction
o Impaired goal-directed behaviour
o Change in the level of anxiety
o Altered stress response (hormones, blood pressure) (change levels of stress
hormones in blood)
• Evidence suggests these roles can be independent of spatial processing, though one could
argue navigation links
(Kluver & Bucy, 1939) - Hpp lesions in monkeys —> aggressive, emotional and sexual deviation;
profound effects on emotional behaviour
There is much evidence across species for both hot and cold hippocampus
Can these two viewpoints be resolved?
Gross Anatomy of Hippocampus
• The circuit is the same throughout entire length (ventral - dorsal); tri-synaptic loop
o But does the whole length do the same thing?
• Brain classically split into evolutionary ancient emotional ventral structures (hot) and
cognitive (cold) dorsal structures; ventral = hot, emotional; dorsal = cold, cognitive
• Most studies that say the hippocampus is purely spatial almost entirely focus on dorsal
structures
o Many studies that say hippocampus is emotional tend to focus on ventral
§ Could be coincidence?
Are dorsal (cold) and ventral (hot) hippocampus actually different structures with different roles?
Dorsal-Ventral Dichotomy?
(Strange et al. 2014)
