The hippocampus occupies a structurally and functionally central position across the depth-psychology corpus, appearing most consistently as the neural substrate of explicit, declarative, and spatial memory. Kandel's sustained research programme—spanning cellular electrophysiology, place-cell mapping, and molecular biology—provides the corpus's most detailed treatment, tracing the hippocampus from its pyramidal-cell architecture through long-term potentiation to its role in spatial cognition and age-related memory decline. Milner's classical work on H.M. establishes the hippocampus as necessary for the consolidation of new explicit memories, a finding that anchors the entire field. The trauma literature, represented by Lanius and Ogden, shifts the register dramatically: here the hippocampus appears as a structure diminished by chronic stress, its volumetric atrophy and functional deficits mediating the fragmented, dysregulated memory characteristic of PTSD, with neurogenesis offering a potential therapeutic vector. Burnett adds an evolutionary dimension, arguing for the co-development of hippocampal navigation and olfactory memory systems. Panksepp and Mohandas extend the hippocampus into affective neuroscience and altered states, connecting it to the SEEKING system's theta rhythms and to meditation-induced shifts in perfusion. Across these positions, a productive tension persists between the hippocampus as a site of constructive spatial and episodic encoding and as a structure rendered vulnerable by overwhelming experience.
In the library
21 passages
The hippocampus is required for the storage of explicit memory. A structure lying deep in the temporal lobe of the cerebral hemispheres. The hippocampus, the dentate gyrus, and the subiculum constitute the hippocampal formation.
This glossary entry establishes the canonical definition of the hippocampus in memory science, identifying it as the obligatory structure for explicit memory storage and situating it within the broader hippocampal formation.
Kandel, Eric R., In search of memory the emergence of a new science of mind, 2006thesis
Squire (1992) argues that the hippocampus plays a specialized role in the consolidation of declarative memory. Bilateral removal of the hippocampus in H. M.'s case, and bilateral damage in Korsakoff's syndrome…abolished or impaired the ability to form new declarative memories.
Drawing on Squire's systems-level framework and H.M.'s bilateral hippocampectomy, this passage argues that the hippocampus is specifically required for declarative memory consolidation while leaving procedural memory intact.
James, William, The Principles of Psychology, 1890thesis
neurons in the hippocampus of the rat register information not about a single sensory modality…but about the space surrounding the animal…the hippocampus of rats contains a representation—a map—of external space and…the pyramidal cells of the hippocampus…process information about place.
Reporting O'Keefe's discovery of place cells, this passage argues that the hippocampus functions as a spatial mapping system whose pyramidal neurons encode location rather than any single sensory modality.
Kandel, Eric R., In search of memory the emergence of a new science of mind, 2006thesis
Both hippocampal atrophy and hippocampal-based memory deficits were reversed with treatment with the selective serotonin reuptake inhibitor paroxetine, which has been shown to promote neurogenesis in the hippocampus in preclinical studies.
This passage argues that stress-induced hippocampal atrophy in PTSD is not permanent but reversible through pharmacological promotion of neurogenesis, linking hippocampal volume to treatable memory dysregulation.
Lanius, edited by Ruth A, The impact of early life trauma on health and disease the, 2010thesis
the pyramidal cells of the hippocampus…thought to be the key hippocampal cells involved in memory storage…the unique functions of the hippocampus had to arise not so much from the intrinsic properties of pyramidal neurons but from the pattern of functional interconnections of these cells.
Kandel argues that the hippocampus's mnemonic distinctiveness derives from its circuitry of interconnections rather than from any intrinsic property of its pyramidal neurons, redirecting the question of memory storage toward network organisation.
Kandel, Eric R., The Molecular Biology of Memory Storage: A Dialogue between Genes and Synapses, 2001thesis
O'Keefe had discovered place cells in 1971, and Bliss and Lømo had discovered long-term potentiation in the hippocampus in 1973, no attempt had been made to connect the two findings.
This passage identifies the unexplored link between place-cell mapping and long-term potentiation in the hippocampus as a key intellectual frontier, arguing for the convergence of spatial and molecular memory research.
Kandel, Eric R., In search of memory the emergence of a new science of mind, 2006thesis
the olfactory system and the hippocampus evolved together; they influenced each other's development because they're fundamentally linked…the hippocampus records locations of the useful landmarks around us…allowing us to work out where we are and where we're going.
Burnett advances an evolutionary argument that the hippocampus's navigation function and its tight coupling to olfaction reflect co-evolutionary origins, with landmark-based spatial encoding as the hippocampus's foundational operation.
Burnett, Dean, The emotional brain lost and found in the science of, 2023thesis
the decline in hippocampus-dependent learning in older animals is due, at least in part, to an age-related deficit in the late phase of long-term potentiation…benign senescent forgetfulness may be reversible.
This passage links age-related hippocampal memory decline to a specific molecular deficiency in late-phase long-term potentiation, suggesting that senescent forgetting is a tractable pharmacological target.
Kandel, Eric R., In search of memory the emergence of a new science of mind, 2006supporting
dopamine modulates the amount of the prion-like CPEB protein (CPEB-3) in the mouse hippocampus…spatial maps may become fixed when an animal's attention triggers the release of dopamine in the hippocam[pus].
This passage proposes that attentionally recruited dopamine stabilises spatial maps in the hippocampus through prion-like protein mechanisms analogous to those found in Aplysia long-term memory.
Kandel, Eric R., In search of memory the emergence of a new science of mind, 2006supporting
dopamine prompts a receptor in the hippocampus to activate an enzyme that increases the amount of cyclic AMP…the cyclic AMP recruits protein kinase A and other protein kinases, which leads to the activation of CREB and the turning on of effector genes.
Kandel traces the molecular cascade by which dopamine-driven late-phase long-term potentiation in the hippocampus mirrors serotonin-driven plasticity in Aplysia, converging on CREB-mediated gene expression.
Kandel, Eric R., In search of memory the emergence of a new science of mind, 2006supporting
To understand how the neural circuitry of the hippocampus affects memory storage, we needed to know how sensory information reaches the hippocampus, what happens to it there, and where it goes after it leaves the hippocampus.
This passage frames the central research problem of hippocampal memory science as a question of input-output circuitry—how sensory signals enter, are transformed by, and exit the hippocampus.
Kandel, Eric R., In search of memory the emergence of a new science of mind, 2006supporting
even ambient attention is suffici[ent]…Attention also allows us to bind the various components of a spatial image into a unified whole.
Through experiments manipulating attentional demand, this passage argues that attention is a prerequisite for the formation and stability of the hippocampal spatial map.
Kandel, Eric R., In search of memory the emergence of a new science of mind, 2006supporting
O'Keefe applied this Kantian logic about space to explicit memory. He argued that many forms of explicit memory…use spatial coordinates—that is, we typically remember people and events in a spatial context.
Situating O'Keefe's place-cell research within Kantian epistemology, this passage argues that the hippocampus implements an a priori spatial framework that organises all forms of explicit memory.
Kandel, Eric R., In search of memory the emergence of a new science of mind, 2006supporting
mice use three strategies in sequence: random, serial, and spatial. Each strategy allows the animals to find the escape hatch…Neither strategy is spatial—neither requires the mice to have an int[ernal map]
This behavioural experiment demonstrates the developmental trajectory of spatial strategy acquisition, implicitly requiring hippocampal function for the final, map-based escape strategy.
Kandel, Eric R., In search of memory the emergence of a new science of mind, 2006supporting
the SEEKING system with higher brain mechanisms, such as the frontal cortex and hippocampus, that generate plans by mediating higher-order temporal and spatial information processing…circuits coursing through the LH can trigger a hippocampal theta rhythm.
Panksepp positions the hippocampus as an integrative node within the SEEKING system, where theta rhythms signal its involvement in higher-order temporal and spatial planning linked to motivational circuitry.
Panksepp, Jaak, Affective Neuroscience The Foundations of Human and Animal, 1998supporting
we found that unlike motor neurons, a certain class of hippocampal neurons fires spontaneously…action potentials in the pyramidal cells of the hippocampus originate at more than one site within the cell.
Reporting early electrophysiological findings, this passage establishes that hippocampal pyramidal cells have distinctive firing properties—spontaneous activity and multiple action-potential initiation sites—that distinguish them from motor neurons.
Kandel, Eric R., In search of memory the emergence of a new science of mind, 2006supporting
meditation is accompanied by a relatively increased perfusion in the sensory imagery system: hippocampus and sensory and higher order association regions, with decreased perfusion in the executive system.
PET imaging evidence here positions the hippocampus as part of a sensory-imagery network whose activity increases during meditative states inverse to executive-system deactivation.
Mohandas, E., Neurobiology of Spirituality, 2008supporting
the hippocampal formation and its interconnected cortices, e.g., entorhinal cortex (area 28) and the perirhinal cortices (area 35)…are not required to implement the proto-self.
Damasio's exclusion of the hippocampal formation from the proto-self's neural substrate clarifies its functional scope, assigning it to higher-order memory and consciousness rather than to the foundational body-state representation.
Damasio, Antonio R., The Feeling of What Happens: Body and Emotion in the Making of Consciousness, 1999supporting
L. hippocampus/amygdala -19 -16 [negative correlation with chills intensity]
Neuroimaging data show that hippocampal and amygdaloid activity decreases as the subjective intensity of musical chills increases, placing the hippocampus in a network that is deactivated during peak aesthetic-emotional experience.
Blood, Anne J., Intensely Pleasurable Responses to Music Correlate with Activity in Brain Regions Implicated in Reward and Emotion, 2001aside
memory formation in the human hippocampus and nucleus accumbens…Rhinal-hippocampal interactions during deja vu.
Bibliographic references here implicate the hippocampus in memory consolidation and in the déjà vu phenomenon through rhinal-hippocampal interactions, connecting it to entropic theories of consciousness.
Carhart-Harris, Robin, The Entropic Brain: A Theory of Conscious States Informed by Neuroimaging Research with Psychedelic Drugs, 2014aside