Distribution and analysis of hippocampal theta-related cells in the pontine region of the urethane-anesthetized rat

Hanada, Yasuhiro; Hallworth, Nicholas E.; Szgatti, Tina L.; Scarlett, Darren; Bland, Brian H.

doi:10.1002/(sici)1098-1063(1999)9:3<288::aid-hipo8>3.0.co;2-a

Cited by 27 publications

(10 citation statements)

References 37 publications

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“…In later studies, theta‐on and theta‐off cells were reported at all levels of the ascending brainstem hippocampal synchronizing pathway, i.e. in the pontine region (Vertes & Kocsis, ; Hanada et al .,), caudal diencephalon (Bland et al ., ; Kirk et al ., ) and medial septal area (Ford et al ., ; Bland et al ., ), and in most limbic structures: hippocampal formation (McNaughton et al ., ; Colom & Bland, ; Mizumori et al ., ; Bland et al ., ; Konopacki et al ., ), entorhinal cortex (Dickson et al ., , ), cingulate cortex (Colom et al ., ) and finally neocortex (Lukatch & MacIver, , ). The presence of theta‐related cells in all of those structures indicates that those neurons form the structural foundations of the oscillations and synchrony phenomena occurring in the CNS's neuronal networks (Bland & Colom, ).…”

Section: In Vitro Recorded Theta Rhythmmentioning

confidence: 96%

The generation of theta rhythm in hippocampal formation maintainedin vitro

Kowalczyk

Bocian

Konopacki

2012

Eur J of Neuroscience

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The most spectacular example of oscillations and synchrony which appear in the brain is the rhythmic slow activity (theta) of the limbic cortex. Theta rhythm is the best synchronized electroencephalographic activity that can be recorded from the mammalian brain. Hippocampal formation is considered to be the main structure involved in the generation of this activity. Although detailed studies of the physiology and pharmacology of theta-band oscillations have been carried out since the early 1950s, the first demonstration of atropine-sensitive theta rhythm, recorded in completely deafferented hippocampal slices of a rat, was performed in the second half of the 1980s. Since the discovery of cholinergically induced in vitro theta rhythm recorded from hippocampal formation slices, the central mechanisms underlying theta generation have been successfully studied in in vitro conditions. Most of these experiments were focused on the basic question regarding the similarities between the cholinergically induced theta activity and theta rhythm examined in vivo. The results of numerous in vitro experiments strongly suggest that cholinergically induced theta rhythm recorded in hippocampal slices is a useful analogue of theta observed in intact animals, and could be helpful in searching for the mechanisms of oscillations and synchrony in the central nervous system neuronal networks. The objective of the present review is to discuss the main results of experiments concerning theta oscillations recorded in in vitro conditions. It is our intent to provide, on the basis of these results, the characteristics of essential mechanisms underlying the generation of atropine-sensitive in vitro theta.

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Section: In Vitro Recorded Theta Rhythmmentioning

confidence: 96%

The generation of theta rhythm in hippocampal formation maintainedin vitro

Kowalczyk

Bocian

Konopacki

2012

Eur J of Neuroscience

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“…Interest in θ has flourished from the abundant data indicating that the rhythm is linked with integrative processes critical for higher cognitive functions. Thus, neuronal spiking in widespread brain regions is phase locked to hippocampal θ oscillations, including somatosensory, entorhinal, or prefrontal cortices Nuñez et al, 1991Nuñez et al, , 2006Kocsis and Vertes, 1994;Hanada et al, 1999;Sirota et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

The Theta Rhythm of the Hippocampus: From Neuronal and Circuit Mechanisms to Behavior

Núñez

Buño

2021

Front. Cell. Neurosci.

114

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This review focuses on the neuronal and circuit mechanisms involved in the generation of the theta (θ) rhythm and of its participation in behavior. Data have accumulated indicating that θ arises from interactions between medial septum-diagonal band of Broca (MS-DbB) and intra-hippocampal circuits. The intrinsic properties of MS-DbB and hippocampal neurons have also been shown to play a key role in θ generation. A growing number of studies suggest that θ may represent a timing mechanism to temporally organize movement sequences, memory encoding, or planned trajectories for spatial navigation. To accomplish those functions, θ and gamma (γ) oscillations interact during the awake state and REM sleep, which are considered to be critical for learning and memory processes. Further, we discuss that the loss of this interaction is at the base of various neurophatological conditions.

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“…Such theta-related cells comprised two distinct populations termed theta-ON and theta-OFF, first described in acute preparations using extracellular recordings by , followed by a detailed cell classification paper by Colom and and subsequently used to classify theta-related cells in the HPC in a number of studies (Bland andColom 1988, 1989;Bland et al 1996;Konopacki et al 1992;. Theta-ON and -OFF cells have also been recorded in the medial septal nucleus and nucleus of the diagonal band of Broca (MS/vDBB) (Bland et al 1990(Bland et al , 1994Ford et al 1989), the entorhinal cortex (Dickson et al 1994(Dickson et al , 1995, cingulate cortex (Colom et al 1988), caudal diencephalon (Bland et al 1995;Kirk et al 1996), rostral pontine region (Hanada et al 1999), the superior colliculus (Natsume et al 1999), the basal ganglia (Hallworth and Bland 1999), the red nucleus (A. Dypvik and B. H. Bland, unpublished data), and the neocortex (Lukatch and MacIver 1996; but see review by Buzsaki 2002 that does not acknowledge the literature on theta-ON and theta-OFF cells). The preceding data suggest, because many regions of the brain from the lower brain stem to the cerebral cortex display "theta-related" neuronal activity, that theta-ON and -OFF cells may represent a general organization of the cellular mechanisms underlying "theta band" oscillation and synchrony (Bland 2000;Bland and Oddie 1998).…”

Section: Introductionmentioning

confidence: 99%

Relationship Between Membrane Potential Oscillations and Rhythmic Discharges in Identified Hippocampal Theta-Related Cells

Bland

Konopacki

Dyck

2002

Journal of Neurophysiology

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Intracellular recordings of cells, classified according to the criteria of Colom and Bland as phasic theta-ON or phasic theta-OFF cells, were carried out in the dorsal region of the hippocampal formation in urethan-anesthetized rats. Cells were studied during two spontaneously occurring hippocampal field conditions, asynchrony, termed large-amplitude irregular activity, and synchrony, termed theta. During the spontaneous cycling between these two field states, the effect of four levels of intracellular depolarizing and hyperpolarizing constant current injections on the amplitude and phase of membrane potential oscillations (MPOs) and the rate and pattern of cell discharges was assessed. Labeled CA1 pyramidal cells and bistratified cells met the criteria for classification as phasic theta-ON cells and labeled CA1 pyramidal layer basket cells, mossy hilar cells, and granule cells met the criteria for classification as phasic theta-OFF cells. MPOs were recorded in CA1 pyramidal cells, CA1 layer basket cells, mossy interneurons, and granule cells only during theta field activity, their onset in theta-ON cells signaled by a depolarizing shift of 5-10 mV and in theta-OFF cells by a hyperpolarizing shift of 5-10 mV, in membrane potential. The effect of current injections in phasic theta-ON and theta-OFF cells during the theta field condition revealed that MPO amplitude was voltage dependent and frequency was voltage independent. There were no phase changes observed in phasic theta-ON cells during current injections; however, amplitude analysis revealed an inverted U-shaped curve asymmetrically distributed around the average value of the membrane potential occurring during the spontaneous theta (no current) control condition. The occurrence and rate of rhythmical cell discharges in CA1 pyramidal phasic theta-ON cells during the theta condition was precisely controlled within a critical range of membrane potential values from approximately -57 to -68 mV, corresponding to a range of MPO amplitudes of approximately 4-7 mV. Outside the critical range, rhythmic cell discharges were abolished. Membrane potential oscillations in CA1 pyramidal layer basket cells underwent an approximate 180 degrees phase reversal when the membrane potential was depolarized above -65 mV. The occurrence and rate of rhythmic cell discharges in CA1 pyramidal layer basket cell phasic theta-OFF cells during the theta condition was precisely controlled within a critical range of membrane potential values from approximately -62 to -60 mV, corresponding to a range of MPO amplitudes of approximately 7-7.5 mV. Outside the critical range, cell discharges were absent or occurred singly.

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Distribution and analysis of hippocampal theta-related cells in the pontine region of the urethane-anesthetized rat

Cited by 27 publications

References 37 publications

The generation of theta rhythm in hippocampal formation maintainedin vitro

The generation of theta rhythm in hippocampal formation maintainedin vitro

The Theta Rhythm of the Hippocampus: From Neuronal and Circuit Mechanisms to Behavior

Relationship Between Membrane Potential Oscillations and Rhythmic Discharges in Identified Hippocampal Theta-Related Cells

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