Hippocampal Place Cells Are Not Controlled by Visual Input during the Small Irregular Activity State in the Rat

Jarosiewicz, Beata; Skaggs, William E.

doi:10.1523/jneurosci.5650-03.2004

Cited by 27 publications

(30 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These neurons tend to hyperpolarize across transitions to LIA (Figure 2), depolarize across transitions to SIA (Figure 3), and hyperpolarize around ripples (Figure 5 E and S3 E). The activity of these neurons is consistent with previous studies that have described a subset of principal neurons that show a robust increase in activity during SIA and may code for spatial position in the absence of locomotion and associated theta oscillations (Jarosiewicz et al, 2002, Jarosiewicz and Skaggs, 2004b, Jarosiewicz and Skaggs, 2004a, Kay et al, 2016). …”

Section: Discussionsupporting

confidence: 90%

Brain State Dependence of Hippocampal Subthreshold Activity in Awake Mice

2017

View full text Add to dashboard Cite

Summary Monitoring the membrane potential of individual neurons has uncovered how single-cell properties contribute to network processing across different brain states in neocortex. In contrast, the subthreshold modulation of hippocampal neurons by brain state has not been systematically characterized. To address this, we combined whole-cell recordings from dentate granule cells and CA1 pyramidal neurons with multisite extracellular recordings and behavioral measurements in awake mice. We show that the average membrane potential, amplitude of subthreshold fluctuations, and distance to spike threshold are all modulated by brain state. Furthermore, even within individual states, rapid variations in arousal are reflected in membrane potential fluctuations. These factors produce depolarizing ramps in the membrane potential of hippocampal neurons that precede ripples and mirror transitions to a network regime conducive for ripple generation. These results suggest that there are coordinated shifts in subthreshold dynamics of individual neurons that underlie the transitions between distinct modes of hippocampal processing.

show abstract

Section: Discussionsupporting

confidence: 90%

Brain State Dependence of Hippocampal Subthreshold Activity in Awake Mice

2017

View full text Add to dashboard Cite

show abstract

“…As described by Jarosiewicz and Skaggs (2004a), SIA represents a brain state more aroused than REM or slow-wave sleep, and less than that of waking. SIA can be observed during sleep transitions or when aroused from deep sleep (Leung et al 1982) and seems to involve activation of a subset of hippocampal neurons that code for the spatial position in which the animal fell asleep (Jarosiewicz and Skaggs 2004b). Given the results presented .…”

Section: Discussionmentioning

confidence: 75%

Median Raphe Stimulation Disrupts Hippocampal Theta Via Rapid Inhibition and State-Dependent Phase Reset of Theta-Related Neural Circuitry

Jackson

Dickson²,

Bland³

2008

Journal of Neurophysiology

View full text Add to dashboard Cite

Jackson J, Dickson CT, Bland BH. Median raphe stimulation disrupts hippocampal theta via rapid inhibition and state-dependent phase reset of theta-related neural circuitry. J Neurophysiol 99: 3009 -3026, 2008. First published April 24, 2008 doi:10.1152/jn.00065.2008. Evidence has accumulated suggesting that the median raphe (MR) mediates hippocampal theta desynchronization. However, few studies have evaluated theta-related neural circuitry during MR manipulation. In urethane-anesthetized rats, we investigated the effects of MR stimulation on hippocampal field and cell activity using high-frequency (100 Hz), theta burst (TBS), and slow-frequency electrical stimulation (0.5 Hz). We demonstrated that high-frequency stimulation of the MR did not elicit deactivated patterns in the forebrain, but rather elicited lowvoltage activity in the neocortex and small-amplitude irregular activity (SIA) in the hippocampus. Both hippocampal phasic theta-ON and -OFF cells were inhibited by high-frequency MR stimulation, although MR stimulation failed to affect cells that had neither state or phase relationships with theta field activity. TBS of the MR-induced theta field activity phase locked to the stimulation. Slow-frequency stimulation elicited a state-dependent reset of theta phase through a short-latency inhibition (5 ms) in phasic theta-ON cells. Subpopulations of phasic theta-ON cells responded in either oscillatory or nonoscillatory patterns to MR pulses, depending on their intraburst interval. OFF cells exhibited a state-dependent modulation of cell firing occurring preferentially during nontheta. The magnitude of MRinduced reset varied as a function of the phase of the theta oscillation when the pulse was administered. Therefore high-frequency stimulation of the MR appears to disrupt hippocampal theta through a state-dependent, short-latency inhibition of rhythmic cell populations in the hippocampus functioning to switch theta oscillations to an activated SIA field state.

show abstract

“…Hippocampal pyramidal cells, called place cells in rodents, each selectively fire at a high rate when the animal is located in a particular spatial domain, called a place field of the place cell. This type of firing is observed during active maze running (O'Keefe and Dostrovsky 1971), and to some extent, during slow-wave sleep states (Wilson and McNaughton 1994;Jarosiewicz et al 2002;Lee and Wilson 2002;Jarosiewicz and Skaggs 2004). Equivalent or similar phenomena were observed in primates (Rolls and O'Mara 1995;Robertson et al 1998), including humans (Ekstrom et al 2003).…”

mentioning

confidence: 60%

A simple neural network model of the hippocampus suggesting its pathfinding role in episodic memory retrieval

Samsonovich¹,

Ascoli²

2005

Learn. Mem.

View full text Add to dashboard Cite

The goal of this work is to extend the theoretical understanding of the relationship between hippocampal spatial and memory functions to the level of neurophysiological mechanisms underlying spatial navigation and episodic memory retrieval. The proposed unifying theory describes both phenomena within a unique framework, as based on one and the same pathfinding function of the hippocampus. We propose a mechanism of reconstruction of the context of experience involving a search for a nearly shortest path in the space of remembered contexts. To analyze this concept in detail, we define a simple connectionist model consistent with available rodent and human neurophysiological data. Numerical study of the model begins with the spatial domain as a simple analogy for more complex phenomena. It is demonstrated how a nearly shortest path is quickly found in a familiar environment. We prove numerically that associative learning during sharp waves can account for the necessary properties of hippocampal place cells. Computational study of the model is extended to other cognitive paradigms, with the main focus on episodic memory retrieval. We show that the ability to find a correct path may be vital for successful retrieval. The model robustly exhibits the pathfinding capacity within a wide range of several factors, including its memory load (up to 30,000 abstract contexts), the number of episodes that become associated with potential target contexts, and the level of dynamical noise. We offer several testable critical predictions in both spatial and memory domains to validate the theory. Our results suggest that (1) the pathfinding function of the hippocampus, in addition to its associative and memory indexing functions, may be vital for retrieval of certain episodic memories, and (2) the hippocampal spatial navigation function could be a precursor of its memory function.The phenomenon of hippocampal spatial representations and the hippocampal role in episodic memory retrieval remain two of the most puzzling mysteries in cognitive neuroscience that intuitively seem to be connected to each other. Since the finding that the hippocampus plays a pivotal role in long-term memory consolidation (Scoville and Milner 1957; Zola-Morgan and Squire 1986), many proposals have been made regarding its specific role (Teyler and Discenna 1985;Squire 1987;O'Reilly and McClelland 1994;McClelland et al. 1995). A prominent view of the mechanisms underlying consolidation of episodic memories involves fast formation (e.g., via Hebbian mechanisms) of strong associations between hippocampal sparse patterns of activity and distributed neocortical representations. As a result, the former subsequently serve as pointers to the latter. This memory-indexing theory that goes back to Teyler andDiscenna (1985, 1986) and underlies several subsequent major theoretical contributions to the field (Nadel and Wheeler et al. 1997;Tulving 2002) assumes that a memory of an episode is retrieved by reactivating a hippocampal pointer to it. Consistent with this view, r...

show abstract

Hippocampal Place Cells Are Not Controlled by Visual Input during the Small Irregular Activity State in the Rat

Cited by 27 publications

References 37 publications

Brain State Dependence of Hippocampal Subthreshold Activity in Awake Mice

Brain State Dependence of Hippocampal Subthreshold Activity in Awake Mice

Median Raphe Stimulation Disrupts Hippocampal Theta Via Rapid Inhibition and State-Dependent Phase Reset of Theta-Related Neural Circuitry

A simple neural network model of the hippocampus suggesting its pathfinding role in episodic memory retrieval

Contact Info

Product

Resources

About