The Hippocampus Synapses Circuits Lecture Twelve Circuits The

The Hippocampus Synapses & Circuits Lecture Twelve

Circuits

The Hippocampus is Magical

The Hippocampus

The Hippocampus

Hippocampus: Main Pathways Hippocampus CA 1 Subiculum Schaffer Collateral DG CA 3 ber y Fi Moss Layer V/VI Tem por Entorhinal Cortex oam Pat mon ic h Perforant Path Layer III Layer II

Hippocampus: Main Pathways Hippocampus CA 1 Subiculum Schaffer Collateral DG CA 3 ber y Fi Moss Layer V/VI Tem por Entorhinal Cortex oam Pat mon ic h Perforant Path Layer III Layer II

Hippocampus: Main Pathways Hippocampus CA 1 Subiculum Schaffer Collateral DG CA 3 ber y Fi Moss Layer V/VI Tem por Entorhinal Cortex oam Pat mon ic h Perforant Path Layer III Layer II Encodes, associates, consolidates & recalls representations of the external & internal world. Code is found within the combined firing rates & spike times of glutamatergic pyramidal & granule cells. Associates specific life events (items, episodes) in temporally determined firing sequences of neuronal assemblies. Great interneuron diversity (up to 21 types in CA 1 alone).

Hippocampus: Main Pathways Hippocampus CA 1 Subiculum Schaffer Collateral DG CA 3 ber y Fi Moss Layer V/VI Tem por Entorhinal Cortex oam Pat mon ic h Perforant Path Layer III Layer II

Hippocampus: Main Pathways Hippocampus CA 1 Subiculum Schaffer Collateral DG CA 3 ber y Fi Moss Layer V/VI Tem por Entorhinal Cortex oam Pat mon ic h Perforant Path Layer III Layer II L III L V/VI EC

Hippocampus: Main Pathways CA 1 Hippocampus Subiculum Schaffer Collateral DG ber CA 3 y Fi Moss Layer V/VI Tem por Path L III EC Layer III Layer II Molecular Layer Granule Cell Layer Entorhinal Cortex oam Pat mon ic h Perforant DG Sik et al. , 1997 L V/VI Hilus

Hippocampus: Main Pathways CA 1 Hippocampus Subiculum Schaffer Collateral DG ber CA 3 y Fi Moss Layer V/VI Tem por Path Molecular Layer L III EC Granule Cell Layer Molecular Layer DG Pyramidal Cell Layer L V/VI Hilus Stratum Oriens CA 3 Entorhinal Cortex oam Pat mon ic h Perforant Stratum Lacunosum. Moleculare Stratum Radiatum Stratum Lucidum Layer III Layer II

Hippocampus: Main Pathways CA 1 Hippocampus Subiculum Schaffer Collateral DG ber CA 3 y Fi Moss Layer V/VI Tem por Path Molecular Layer L III EC Granule Cell Layer Molecular Layer DG Pyramidal Cell Layer CA 3 Stratum Lacunosum. Moleculare Stratum Radiatum Stratum Lucidum Molecular Layer CA 1 L V/VI Hilus Stratum Oriens Entorhinal Cortex oam Pat mon ic h Perforant Pyramidal Cell Stratum Oriens Layer III Layer II

Hippocampus: Main Pathways CA 1 Hippocampus Subiculum Schaffer Collateral DG ber CA 3 y Fi Moss Layer V/VI Tem por Entorhinal Cortex oam Pat mon ic h Perforant Path Molecular Layer L III EC Granule Cell Layer Molecular Layer DG Pyramidal Cell Layer CA 3 Stratum Lacunosum. Moleculare Stratum Radiatum Stratum Lucidum Molecular Layer CA 1 L V/VI Hilus Stratum Oriens Pyramidal Cell Stratum Oriens Layer III Layer II Molecular Layer Pyramidal Cell Layer Sub

Hippocampus: Main Pathways CA 1 Hippocampus Subiculum Schaffer Collateral DG ber CA 3 y Fi Moss Layer V/VI Tem por Entorhinal Cortex oam Pat mon ic h Perforant Path Molecular Layer L III EC Granule Cell Layer Molecular Layer DG Pyramidal Cell Layer CA 3 Stratum Lacunosum. Moleculare Stratum Radiatum Stratum Lucidum Molecular Layer CA 1 L V/VI Hilus Stratum Oriens Pyramidal Cell Stratum Oriens Layer III Layer II Molecular Layer Pyramidal Cell Layer Sub

Hippocampus: Main Pathways Molecular Layer L III EC Granule Cell Layer Molecular Layer DG Pyramidal Cell Layer CA 3 Stratum Lacunosum. Moleculare Stratum Radiatum Stratum Lucidum Molecular Layer CA 1 L V/VI Hilus Stratum Oriens Pyramidal Cell Stratum Oriens Layer Molecular Layer Pyramidal Cell Layer Sub

Hippocampus: Main Pathways van Strien et al. , 2009 L III L V/VI EC DG CA 3 CA 1 Sub

Hippocampus: Main Pathways Thalamus Muller & Remy, 2017 L III L V/VI EC DG CA 3 CA 1 Sub

Hippocampus: Main Pathways Thalamus Muller & Remy, 2017 L III L V/VI EC DG CA 3 CA 1 Sub

Hippocampus: Main Pathways So, what do you do for a living? L III L V/VI EC DG CA 3 CA 1 Sub

Hippocampus: Main Pathways Learn Stuff L III L V/VI EC Navigate Stuff DG CA 3 Separate Stuff CA 1 Sub

Couldn’t have said it better. Hippocampus: Physiology Organizing Principles A Functional Sandwich: strongly recurrent excitatory networks are sandwiched between layers of parallel organization. Neuronal representations can be iteratively segregated (parallel stages) and integrated (recursive stages) in successive layers. It Takes Time: Local parallelization and integration require computational time before moving forward. Speed of local processing and layer-to-layer transfer is controlled by “traffic controllers” (i. e. inhibitory interneurons). Oscillations Emerge: Dynamics between pyramidal cells & interneurons often manifest as population-wide, electrical oscillations. Oscillations, in general, impose a spatiotemporal structure on neural ensembles within and across networks. L III L V/VI EC DG CA 3 CA 1 Sub

Couldn’t have said it better. Hippocampus: Physiology Major Network Patterns theta: 4 -10 Hz. Competing states Associated with exploratory (“preparatory”) movement & REM sleep. cortical hippocampal information transfer. sharp waves & ripples: 140 -200 Hz. Associated with immobility, consummatory behaviors & slow-wave sleep. hippocampal cortical information transfer. gamma: 30 -80 Hz. Present in all cortical & other structures where fast inhibition is provided by soma-targeting interneurons. Frequency largely determined by GABAA inhibition. Neurons that discharge within the time period of a gamma cycle define a cell “assembly”. L III L V/VI EC DG CA 3 CA 1 Sub

Couldn’t have said it better. Hippocampus: Physiology Major Network Patterns theta: 4 -10 Hz. Competing states Associated with exploratory (“preparatory”) movement & REM sleep. cortical hippocampal information transfer. sharp waves & ripples: 140 -200 Hz. Associated with immobility, consummatory behaviors & slow-wave sleep. hippocampal cortical information transfer. gamma: 30 -80 Hz. Present in all cortical & other structures where fast inhibition is provided by soma-targeting interneurons. Frequency largely determined by GABAA inhibition. Neurons that discharge within the time period of a gamma cycle define a cell “assembly”. L III L V/VI EC DG CA 3 CA 1 Sub

Couldn’t have said it better. Hippocampus: Physiology Major Network Patterns theta: 4 -10 Hz. Competing states Associated with exploratory (“preparatory”) movement & REM sleep. cortical hippocampal information transfer. sharp waves & ripples: 140 -200 Hz. Associated with immobility, consummatory behaviors & slow-wave sleep. hippocampal cortical information transfer. gamma: 30 -80 Hz. Present in all cortical & other structures where fast inhibition is provided by soma-targeting interneurons. Frequency largely determined by GABAA inhibition. Neurons that discharge within the time period of a gamma cycle define a cell “assembly”. L III L V/VI EC DG CA 3 CA 1 Sub

Couldn’t have said it better. Hippocampus: Physiology Major Network Patterns theta: 4 -10 Hz. Competing states Associated with exploratory (“preparatory”) movement & REM sleep. cortical hippocampal information transfer. sharp waves & ripples: 140 -200 Hz. Associated with immobility, consummatory behaviors & slow-wave sleep. hippocampal cortical information transfer. gamma: 30 -80 Hz. Present in all cortical & other structures where fast inhibition is provided by soma-targeting interneurons. Frequency largely determined by GABAA inhibition. Neurons that discharge within the time period of a gamma cycle define a cell “assembly”. L III L V/VI EC DG CA 3 CA 1 Sub

Couldn’t have said it better. Hippocampus: Physiology Major Network Patterns theta: 4 -10 Hz. Competing states Associated with exploratory (“preparatory”) movement & REM sleep. cortical hippocampal information transfer. sharp waves & ripples: 140 -200 Hz. Associated with immobility, consummatory behaviors & slow-wave sleep. hippocampal cortical information transfer gamma: 30 -80 Hz. Present in all cortical & other structures where fast inhibition is provided by soma-targeting interneurons. Frequency largely determined by GABAA inhibition. Neurons that discharge within the time period of a gamma cycle define a cell “assembly”. L III L V/VI EC DG CA 3 CA 1 Sub

Couldn’t have said it better. L III L V/VI EC Hippocampus: Physiology DG CA 3 CA 1 Sub

Couldn’t have said it better. L III L V/VI EC Hippocampus: Physiology DG CA 3 CA 1 Sub

Couldn’t have said it better. L III L V/VI EC Hippocampus: Physiology DG CA 3 CA 1 Sub

Couldn’t have said it better. L III L V/VI EC Hippocampus: Physiology DG CA 3 CA 1 Sub

Couldn’t have said it better. L III L V/VI EC Hippocampus: Physiology DG CA 3 CA 1 Sub

Couldn’t have said it better. L III L V/VI EC Hippocampus: Physiology DG CA 3 CA 1 Sub

Couldn’t have said it better. Hippocampus: Physiology Bender et al. , 2016 Septum L III L V/VI EC CA 1 DG CA 3 CA 1 Sub

Couldn’t have said it better. Hippocampus: Physiology Bender et al. , 2016 Septum CA 1 Pyr. Excitability ACh CA 1 Pyr. Disinhibition Glut Theta Time GABA PV Adapted from Muller & Remy, 2017 L III L V/VI EC SST DG CA 3 CA 1 Sub

Couldn’t have said it better. Hippocampus: Physiology Bender et al. , 2016 Septum CA 1 Pyr. Excitability ACh CA 1 Pyr. Disinhibition Glut Theta Time GABA PV Adapted from Muller & Remy, 2017 L III L V/VI EC SST DG CA 3 CA 1 Sub

Couldn’t have said it better. Hippocampus: Physiology CA 1 L III L V/VI EC DG CA 3 CA 1 Sub

Couldn’t have said it better. Hippocampus: Physiology CA 1 Place Field Theta Phase Precession L III L V/VI EC DG CA 3 CA 1 Sub

The Hippocampus is Magical