No evidence for role of extracellular choline-acetyltransferase in generation of gamma oscillations in rat hippocampal slices in vitro

Hollnagel, Jan‐Oliver; Haq, Rizwan ul; Behrens, Christoph; Maslarova, Anna; Módy, István; Heinemann, Uwe

doi:10.1016/j.neuroscience.2014.10.016

Cited by 6 publications

(4 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The sharp waves occurred with an incidence of about 12/min (Figure 4D) and had a superimposed, fast periodic oscillatory component with frequencies of >180 Hz (''ripples''). These properties were similar to sharp wave-ripples in previous reports (Behrens et al, 2005;Hollnagel et al, 2014;Schlingloff et al, 2014). Remarkably, we did not detect any significant differences in the properties of sharp wave-ripples when fueled by sole lactate, even when lactate was present for 1 h (Figures 4C-4F).…”

Section: Lactate Does Not Affect Sharp Wave-ripplessupporting

confidence: 91%

“…To facilitate the induction of sharp wave-ripples in ex vivo slices the concentration of MgSO4 was lowered to 1.2 mM 1 h before starting the experiments (Behrens et al, 2005;Hollnagel et al, 2014). Induction of gamma oscillations was achieved by bath application of the cholinergic receptor agonist acetylcholine (ex vivo slices: 10 µM, and slice cultures: 2 µM; Sigma-Aldrich) and the acetylcholine-esterase inhibitor physostigmine (ex vivo slices: 2 µM, and slice cultures: 0.4 µM; Tocris, Bio-Techne GmbH, Wiesbaden-Nordenstadt, Germany).…”

Section: Recording Solution and Drugsmentioning

confidence: 99%

See 1 more Smart Citation

Lactate Attenuates Synaptic Transmission and Affects Brain Rhythms Featuring High Energy Expenditure

et al. 2020

View full text Add to dashboard Cite

Summary Lactate shuttled from blood, astrocytes, and/or oligodendrocytes may serve as the major glucose alternative in brain energy metabolism. However, its effectiveness in fueling neuronal information processing underlying complex cortex functions like perception and memory is unclear. We show that sole lactate disturbs electrical gamma and theta-gamma oscillations in hippocampal networks by either attenuation or neural bursts. Bursting is suppressed by elevating the glucose fraction in substrate supply. By contrast, lactate does not affect electrical sharp wave-ripple activity featuring lower energy use. Lactate increases the oxygen consumption during the network states, reflecting enhanced oxidative ATP synthesis in mitochondria. Finally, lactate attenuates synaptic transmission in excitatory pyramidal cells and fast-spiking, inhibitory interneurons by reduced neurotransmitter release from presynaptic terminals, whereas action potential generation in the axon is regular. In conclusion, sole lactate is less effective and potentially harmful during gamma-band rhythms by omitting obligatory ATP delivery through fast glycolysis at the synapse.

show abstract

Section: Lactate Does Not Affect Sharp Wave-ripplessupporting

confidence: 91%

Section: Recording Solution and Drugsmentioning

confidence: 99%

Lactate Attenuates Synaptic Transmission and Affects Brain Rhythms Featuring High Energy Expenditure

et al. 2020

View full text Add to dashboard Cite

show abstract

“…The resulting power spectral density (PSD) plots had a resolution of 1.2207 Hz. γ-oscillations were analyzed for various parameters, i.e., peak power spectral density (pPSD), peak frequency (f), area under the curve (AUC), full width at half maximum (FWHM) and inner coherence (TAU) as described in detail earlier [45]. Medians of subdivisions were calculated and used for further statistical analysis.…”

Section: Methodsmentioning

confidence: 99%

Early alterations in hippocampal perisomatic GABAergic synapses and network oscillations in a mouse model of Alzheimer’s disease amyloidosis

et al. 2019

View full text Add to dashboard Cite

Several lines of evidence imply changes in inhibitory interneuron connectivity and subsequent alterations in oscillatory network activities in the pathogenesis of Alzheimer’s Disease (AD). Recently, we provided evidence for an increased immunoreactivity of both the postsynaptic scaffold protein gephyrin and the GABAA receptor γ2-subunit in the hippocampus of young (1 and 3 months of age), APPPS1 mice. These mice represent a well-established model of cerebral amyloidosis, which is a hallmark of human AD. In this study, we demonstrate a robust increase of parvalbumin immunoreactivity and accentuated projections of parvalbumin positive (PV+) interneurons, which target perisomatic regions of pyramidal cells within the hippocampal subregions CA1 and CA3 of 3-month-old APPPS1 mice. Colocalisation studies confirmed a significant increase in the density of PV+ projections labeled with antibodies against a presynaptic (vesicular GABA transporter) and a postsynaptic marker (gephyrin) of inhibitory synapses within the pyramidal cell layer of CA1 and CA3. As perisomatic inhibition by PV+-interneurons is crucial for the generation of hippocampal network oscillations involved in spatial processing, learning and memory formation we investigated the impact of the putative enhanced perisomatic inhibition on two types of fast neuronal network oscillations in acute hippocampal slices: 1. spontaneously occurring sharp wave-ripple complexes (SPW-R), and 2. cholinergic γ-oscillations. Interestingly, both network patterns were generally preserved in APPPS1 mice similar to WT mice. However, the comparison of simultaneous CA3 and CA1 recordings revealed that the incidence and amplitude of SPW-Rs were significantly lower in CA1 vs CA3 in APPPS1 slices, whereas the power of γ-oscillations was significantly higher in CA3 vs CA1 in WT-slices indicating an impaired communication between the CA3 and CA1 network activities in APPPS1 mice. Taken together, our data demonstrate an increased GABAergic synaptic output of PV+ interneurons impinging on pyramidal cells of CA1 and CA3, which might limit the coordinated cross-talk between these two hippocampal areas in young APPPS1 mice and mediate long-term changes in synaptic inhibition during progression of amyloidosis.

show abstract

“…Furthermore, a recent study (Sarkar et al, 2020) provides evidence for a substantial elevation in brain ACh esterase levels upon Abx treatment. Such an increase in the ACh esterase might reduce extracellular ACh concentration and potentially diminish cholinergic gamma oscillations (Hollnagel et al, 2015). Interestingly, chronic Abx treatment leads to an aberrant sleep/awake architecture and a mild reduction in theta power during sleep suggesting a potential reduction of co-occurring gamma oscillations in vivo (Ogawa et al, 2020).…”

Section: Discussionmentioning

confidence: 99%

Antibiotic treatment induces activation of microglia and impairment of cholinergic gamma oscillations in the hippocampus

Çalışkan

French

Heimesaat

et al. 2021

Preprint

View full text Add to dashboard Cite

Antibiotics are widely applied for the treatment of bacterial infections, but their long-term use may lead to gut flora dysbiosis and detrimental effects on brain physiology, behavior as well as cognitive performance. Still, a striking lack of knowledge exists concerning electrophysiological correlates of antibiotic-induced changes in gut microbiota and behavior. Here, we investigated changes in the synaptic transmission and plasticity together with behaviorally-relevant network activities from the hippocampus of antibiotic-treated mice. The prolonged antibiotic treatment led to a strong reduction of myeloid cell pools in bone marrow, circulation and those surveilling the brain. Upon antibiotic treatment, circulating Ly6Chi inflammatory monocytes adopted a proinflammatory phenotype with increased expression of CD40 and MHC II. In the central nervous system, microglia displayed typical signs of activation with elevated CD40 and MHC II expression, as well as increased IL-6 and TNF production. Concomitantly, we detected a substantial reduction in the synaptic transmission in the hippocampal CA1 after antibiotic treatment. In line, carbachol-induced cholinergic gamma oscillation were reduced upon antibiotic treatment while the incidence of hippocampal sharp waves was elevated. These changes were associated with the global changes in the expression of neurotrophin nerve growth factor and inducible nitric oxide synthase, both of which have been shown to influence cholinergic functions. Overall, our study demonstrates that antibiotic-induced changes in the gut microbiome and immune cell function are associated with a drastic reduction in the synaptic transmission and gamma oscillations in the hippocampus, a brain region that is critically involved in mediation of innate and cognitive behavior.

show abstract

No evidence for role of extracellular choline-acetyltransferase in generation of gamma oscillations in rat hippocampal slices in vitro

Cited by 6 publications

References 39 publications

Lactate Attenuates Synaptic Transmission and Affects Brain Rhythms Featuring High Energy Expenditure

Lactate Attenuates Synaptic Transmission and Affects Brain Rhythms Featuring High Energy Expenditure

Early alterations in hippocampal perisomatic GABAergic synapses and network oscillations in a mouse model of Alzheimer’s disease amyloidosis

Antibiotic treatment induces activation of microglia and impairment of cholinergic gamma oscillations in the hippocampus

Contact Info

Product

Resources

About