Auditory sensory gating in hippocampus and reticular thalamic neurons in anesthetized rats

Krause, Michael; Hoffmann, William E.; Hajós, Mihály

doi:10.1016/s0006-3223(02)01463-4

Cited by 119 publications

(102 citation statements)

References 63 publications

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“…In their review, Guillery et al (17) describe the mammalian reticular nucleus as being subdivided into distinct visual-, somatosensory-, and auditory-specific sectors. Relevant to our study, a recent electrophysiological experiment using paired tones in anesthetized rats has clearly shown auditory gating in the auditory portion of the reticular formation (42). In the zebra finch, control injections that missed the Uva (but also lay within the thalamus) also did not retrogradely label the RSd.…”

Section: Discussionsupporting

confidence: 70%

Connections of thalamic modulatory centers to the vocal control system of the zebra finch

Akutagawa

Konishi

2005

Proc. Natl. Acad. Sci. U.S.A.

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The vocal control system of zebra finches shows auditory gating in which neuronal responses to the individual bird's own song vary with behavioral states such as sleep and wakefulness. However, we know neither the source of gating signals nor the anatomical connections that could link the modulatory centers of the brain with the song system. Two of the song-control nuclei in the forebrain, the HVC (used as the proper name) and the interfacial nucleus of the nidopallium, both show auditory gating, and they receive input from the uvaeform nucleus (Uva) in the thalamus. We used a combination of anterograde and retrograde tracing methods to show that the dorsal part of the reticular formation and the medial habenula (MHb) project to the Uva. We also show by choline acetyl transferase immunohistochemistry that the MHb is cholinergic and sends cholinergic fibers to the Uva. Our findings suggest that the Uva might serve as a hub to coordinate neuromodulatory input into the song system. auditory gating ͉ cholinergic ͉ song system ͉ thalamus T he song system is a discrete, interconnected series of brain nuclei in songbirds that controls singing, which is a learned vocal behavior ( Fig. 1) (1). In addition to displaying song motor activity, neurons of most song nuclei selectively respond to playback of the individual bird's own song (BOS) (2). Responses to the BOS are not created de novo in each song nucleus (3) but are relayed from the HVC to a vocal motor pathway that includes the robust nucleus of the arcopallium (RA) and the tracheosyringeal part of the hypoglossal nucleus. Auditory information also is transmitted from the HVC to an anterior forebrain pathway that includes area X within the songbird medial striatum; the nucleus dorsolateralis anterior thalami, pars medialis; the lateral magnocellular nucleus of the anterior nidopallium; and the RA. The source of auditory input to the HVC is thought to be the interfacial nucleus of the nidopallium (NIf), in which selectivity for the BOS is not as exclusive as in the HVC (4). Both the degree and selectivity of BOS-evoked responses in the HVC vary with natural and induced behavioral states such as sleeping, wakefulness, and anesthesia. This phenomenon is called ''auditory gating'' (5) and provides evidence that links the modulation of auditory input with the vocal control system. The first site of gating in the chain of song nuclei is thought to be the NIf (6). However, little is known about the source of signals that control gating in the NIf. Although several candidate sources for neural modulation have been postulated (7,8), the connections between these areas and the song system remain tenuous. The present study provides anatomical evidence that the uvaeform nucleus (Uva), which projects to both the NIf and HVC, receives cholinergic fibers from neurons in the medial habenula (MHb) and also afferents from the nucleus reticularis superior, pars dorsalis (RSd). These thalamic areas are neuromodulatory centers in other vertebrates, suggesting that the Uva in songbirds ma...

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Section: Discussionsupporting

confidence: 70%

Connections of thalamic modulatory centers to the vocal control system of the zebra finch

Akutagawa

Konishi

2005

Proc. Natl. Acad. Sci. U.S.A.

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“…Filtering of repetitive auditory stimulation has also been observed in the pontine reticular formation (PRF) (Bickford et al, 1993;Moxon et al, 1999), in the medial septum (Moxon et al, 1999), in the reticular thalamic nucleus (RTN) (Krause et al, 2003) and in the amygdala (Cromwell et al, 2005). In addition, hippocampal auditory gating is influenced by stimulation of both the PRF and nucleus of the lateral lemniscus (NLL) (Bickford et al, 1993).…”

Section: Compensatory Changesmentioning

confidence: 99%

Altered hippocampal circuit function in C3H α7 null mutant heterozygous mice

et al. 2008

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The α7 subtype of nicotinic receptor is highly expressed in the hippocampus where it is purported to modulate release of the inhibitory neurotransmitter γ-aminobutyric acid (GABA). The α7 receptormediated release of GABA is thought to contribute to hippocampal inhibition (gating) of response to repetitive auditory stimulation. This hypothesis is supported by observations of hippocampal auditory gating deficits in mouse strains with low levels of hippocampal α7 receptors compared to strains with high levels of hippocampal α7 receptors. The difficulty with comparisons between mouse strains, however, is that different strains have different genetic backgrounds. Thus, the observed interstrain differences in hippocampal auditory gating might result from factors other than interstrain variations in the density of hippocampal α7 receptors. To address this issue, hippocampal binding of the α7 receptor-selective antagonist α-bungarotoxin as well as hippocampal auditory gating characteristics were compared in C3H wild type and C3H α7 receptor null mutant heterozygous mice. The C3H α7 heterozygous mice exhibited significant reductions in hippocampal α7 receptors levels and abnormal hippocampal auditory gating compared to the C3H wild type mice. In addition, a general increase in CA3 pyramidal neuron responsivity was observed in the heterozygous mice compared to the wild type mice. These data suggest that decreasing hippocampal α7 receptor density results in a profound alteration in hippocampal circuit function.

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“…Field potentials were amplified, filtered (0.1-100 Hz), displayed, and recorded for on-line and off-line analysis (Spike3 program; Cambridge Electronic Design, Cambridge, UK). Rhythmic synchronized (theta) and large amplitude irregular hippocampal activities were distinguished in the EEG; quantitative EEG analysis was performed by means of fast Fourier transformation (Krause et al, 2003). Power spectrum density of EEG for theta activity was calculated at a peak frequency between 3 and 6 Hz.…”

Section: Electrophysiological Experimentsmentioning

confidence: 99%

Norepinephrine but not Serotonin Reuptake Inhibitors Enhance Theta and Gamma Activity of the Septo-Hippocampal System

Hajós¹,

Hoffmann²,

Robinson³

et al. 2002

Neuropsychopharmacol

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Current neurobiological concepts attribute a central role of the hippocampal formation in cognitive and affective processes. Recent studies indicate that the hippocampus is affected in human depression, and antidepressant drugs induce hippocampal adaptive changes that are thought to be associated with their therapeutic action. In the present study, we investigated the action of various antidepressant drugs on the activity of the septo-hippocampal system, its oscillatory activity in particular. The acute effects of the norepinephrine (NE) reuptake inhibitors reboxetine and desipramine, and the selective serotonin reuptake inhibitor fluvoxamine were evaluated. Extracellular single-unit recordings were performed from the medial septum/diagonal band of Broca (MS/DBv), with simultaneous hippocampal EEG recordings of anesthetized rats. Systemic administration of reboxetine synchronized hippocampal EEG, resulting in a significant increase in power at theta frequency, and an increase in frequency and power of gamma-wave activity. Parallel to EEG synchrony, reboxetine induced or enhanced theta oscillation of MS/DBv neurons. Oscillatory frequencies of MS/DBv neurons were identical, and phase locked to the corresponding hippocamapal theta frequencies. Under the same experimental conditions, reboxetine induced a two-fold increase in extracellular NE (but not serotonin) levels in the hippocampus as revealed by microdialysis. Desipramine, but not the serotonin reuptake inhibitor fluvoxamine, evoked responses similar to those of reboxetine regarding septo-hippocampal theta activity. The present findings indicate that even though both NE and serotonin reuptake inhibitors are clinically effective antidepressant drugs, their action on the septo-hippocampal oscillatory behavior is different. It is presumed that selective NE reuptake inhibitors could modulate various cognitive processes associated with hippocampal oscillatory activity.

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Auditory sensory gating in hippocampus and reticular thalamic neurons in anesthetized rats

Cited by 119 publications

References 63 publications

Connections of thalamic modulatory centers to the vocal control system of the zebra finch

Connections of thalamic modulatory centers to the vocal control system of the zebra finch

Altered hippocampal circuit function in C3H α7 null mutant heterozygous mice

Norepinephrine but not Serotonin Reuptake Inhibitors Enhance Theta and Gamma Activity of the Septo-Hippocampal System

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