Evidence
I. Retrodictive Evidence
Retrodiction—reasoning backward from observed outcomes after the hypothesis—is just as powerful in validating a proposed solution. The primary goal here is to assess whether new research findings can be explained in terms of the IPL mechanism in an interconnected manner.
A. In physiological conditions & artificial systems
Liu S, Pletenev A, Haefner RM, Snyder AC (2026 February) Task learning increases information redundancy of neural responses in macaque visual cortex. Science. 391(6789):1029-1035. PubMed
Vicarious body maps bridge vision and touch in the human brain. Hedger N, Naselaris T, Kay K, Knapen T (2026 February) Nature. 650(8100):173-181. PubMed
Building compositional tasks with shared neural subspaces. Tafazoli S, Bouchacourt FM, Ardalan A, Markov NT, Uchimura M, Mattar MG, Daw ND, Buschman TJ (2026 February) Nature. 650(8100):164-172. PubMed
Large-scale cortical functional networks are organized in structured cycles. van Es MWJ, Higgins C, Gohil C, Quinn AJ, Vidaurre D, Woolrich MW (2025 Aug) Nat Neurosci. 27. PubMed
Left-right-alternating theta sweeps in entorhinal-hippocampal maps of space. Vollan AZ, Gardner RJ, Moser MB, Moser EI (2025 Mar) Nature. 639(8056):995-1005. PubMed
Hippocampal encoding of memories in human infants. Yates TS, Fel J, Choi D, Trach JE, Behm L, Ellis CT, Turk-Browne NB (2025 Mar 21) Science. 387(6740):1316-1320. PubMed
Human olfactory perception embeds fine temporal resolution within a single sniff. Wu Y, Chen K, Xing C, Huang M, Zhao K, Zhou W (2024) Nat Hum Behav. 8(11):2168-2178. PubMed
Chromatin plasticity predetermines neuronal eligibility for memory trace formation. Santoni G, Astori S, Leleu M, Glauser L, Zamora SA, Schioppa M, Tarulli I, Sandi C, Gräff J (2024) Science. PubMed
Higher-order interactions between hippocampal CA1 neurons are disrupted in amnestic mice. Yan C, Mercaldo V, Jacob AD, Kramer E, Mocle A, Ramsaran AI, Tran L, Rashid AJ, Park S, Insel N, Redish AD, Frankland PW, Josselyn SA (2024) Nat Neurosci. PubMed
Barcoding of episodic memories in the hippocampus of a food-campus of a food-caching bird. Chettih SN, Mackevicius EL, Hale S, Aronov D (2024) Cell. 187(8):1922–1935.e20. PubMed
A ubiquitous spectrolaminar motif of local field potential power across the primate cortex. Mendoza-Halliday D, Major AJ, Lee N, Lichtenfeld MJ, Carlson B, Mitchell B, Meng PD, Xiong YS, Westerberg JA, Jia X, Johnston KD, Selvanayagam J, Everling S, Maier A, Desimone R, Miller EK, Bastos AM (2024) Nat. Neurosci. PubMed
Evidence for long-term potentiation in phospholipid membranes. Scott HL, Bolmatov D, Podar PT, Liu Z, Kinnun JJ, Doughty B, Lydic R, Sacci RL, Collier CP, Katsaras J. (2022) PNAS. 119(50):e2212195119. PubMed
Entorhinal cortex directs learning-related changes in CA1 representations Grienberger and Magee (2022) Nature. 611(7936):554-562. PubMed
Invariant stimulus decoding using correlated neuronal fluctuations. Ebrahimi et al., (2022) Nature. 605(7911):713-721. PubMed
Mosquito brains encode unique features of human odour to drive host seeking. Zhao et al., (2022) Nature. May 605(7911):706-712. PubMed
Synaptic correlates of associative fear memory in the lateral amygdala. Choi et al., (2021) Neuron. 109(17):2717-2726. PubMed
Selective filtering of excitatory inputs to nucleus accumbens by dopamine and serotonin. Christoffel et al., (2021) PNAS.118(24):e2106648118. PubMed
Drift in the set of neurons in the primary olfactory cortex that fire in response to an odour. Schoonover et al., (2021) Nature. 594(7864):541-546. PubMed
Largest class of neurons in the visual cortex is not reliably responsive to any of the visual stimuli. de Vries et al., (2020) A large-scale standardized physiological survey reveals functional organization of the mouse visual cortex. Nat Neurosci. 2020 Jan;23(1):138-151. PubMed
Artificial firing of a neuron leads to firing of a set of neurons of the same neuronal order. Chettih SN, Harvey CD (2019) Single-neuron perturbations reveal feature-specific competition in V1. Nature. PubMed
Memory retrieval occurs at a frequency of oscillating extracellular potentials similar to that was present during learning. Vaz AP, Inati SK, Brunel N, Zaghloul KA (2019) Coupled ripple oscillations between the medial temporal lobe and neocortex retrieve human memory. Science. 363:975-978. PubMed
Hotspots of dendritic spine turnover facilitate clustered spine addition and learning and memory. Frank AC, Huang S, Zhou M, Gdalyahu A, Kastellakis G, Silva TK, Lu E, Wen X, Poirazi P, Trachtenberg JT, Silva AJ (2018) Nat Commun. 9(1):422. PubMed
Synapse-specific representation of the identity of overlapping memory engrams. Abdou K, Shehata M, Choko K, Nishizono H, Matsuo M, Muramatsu SI, Inokuchi K (2018) Science. 360(6394):1227-1231. Article
Heterogeneity of neurons in the cortex Studies of cortical neurons show significant heterogeneity in transcriptomic analyses (Tasic et al., 2016
PubMed; Cembrowski et al., 2016 PubMed; Tasic et al., 2018 PubMed; Hodge et al., 2019 PubMed). Evidence by re-interpretation
Spine depolarization without dendritic depolarization. Beaulieu-Laroche L and Harnett MT. 2018. Dendritic spines prevent synaptic voltage clamp. Neuron 97(1): 75–82.e3. PubMed
Dendritic calcium spikes that are related to behavior and cognitive function
Regenerative spikes at the dendritic arbor - a mechanism for internal sense of a place that reflects binding at the time of learning
B. In pathological conditions
Spread of epileptic activity. Jefferys JG (2014) How does epileptic activity spread? Epilepsy Currents. 14(5):289-290. PubMed
Heterogeneity of clinical and pathological findings in Alzheimer's disease
II. Predictions
Simple predictions include demonstration of
a) Formation of IPLs secondary to a new associative learning event at the locations of convergence of pathways through which stimuli from associated stimuli propagate.
b) Transfer of potentials/voltage across abutted spines that belong to different dendrites (mainly belonging to different neurons) across the IPLs in both both directions.
c) Propagation of potentials/voltage from the spine that elicits postsynaptic potentials by the cue stimulus through the IPLs to the inter-LINKed spines during memory retrieval.
Surprising predictions (will post soon)