scholarly journals Electrical Stimulation of the Ear, Head, Cranial Nerve, or Cortex for the Treatment of Tinnitus: A Scoping Review

2016 ◽  
Vol 2016 ◽  
pp. 1-15 ◽  
Author(s):  
Derek J. Hoare ◽  
Peyman Adjamian ◽  
Magdalena Sereda
Keyword(s):  
Electrical Stimulation ◽  
Neuronal Activity ◽  
Neural Activity ◽  
Cranial Nerve ◽  
Auditory Pathway ◽  
External Source ◽  
Acoustic Stimuli ◽  
Permanent Reduction ◽  
The Brain ◽  
Stimulation Of

Tinnitus is defined as the perception of sound in the absence of an external source. It is often associated with hearing loss and is thought to result from abnormal neural activity at some point or points in the auditory pathway, which is incorrectly interpreted by the brain as an actual sound. Neurostimulation therapies therefore, which interfere on some level with that abnormal activity, are a logical approach to treatment. For tinnitus, where the pathological neuronal activity might be associated with auditory and other areas of the brain, interventions using electromagnetic, electrical, or acoustic stimuli separately, or paired electrical and acoustic stimuli, have been proposed as treatments. Neurostimulation therapies should modulate neural activity to deliver a permanent reduction in tinnitus percept by driving the neuroplastic changes necessary to interrupt abnormal levels of oscillatory cortical activity and restore typical levels of activity. This change in activity should alter or interrupt the tinnitus percept (reduction or extinction) making it less bothersome. Here we review developments in therapies involving electrical stimulation of the ear, head, cranial nerve, or cortex in the treatment of tinnitus which demonstrably, or are hypothesised to, interrupt pathological neuronal activity in the cortex associated with tinnitus.

Neural activity triggers Ca waves in hippocampal astrocyte networks

1991 ◽  
Vol 49 ◽  
pp. 148-149
Author(s):  
J.W. Dani ◽  
A. Chernjavsky ◽  
S.J. Smith
Keyword(s):  
Electrical Stimulation ◽  
Neural Activity ◽  
Normal Tissue ◽  
Neural Stimulation ◽  
Cultured Astrocytes ◽  
Neurotransmitter Glutamate ◽  
Hippocampal Astrocytes ◽  
Cultured Slices ◽  
The Brain ◽  
Stimulation Of

Recent findings that the neurotransmitter glutamate can trigger cytoplasmic Ca waves in networks of cultured astrocytes suggest a new range of possible mechanisms for neural-glial interaction and for signalling over distance within the brain. To explore some of these possibilities, we have used confocal microscopy and the Ca indicator fluo-3 to study organotypically cultured slices of rat hippocampus where astrocytes and neurons are intermingled in their normal tissue relationships. We observe that electrical stimulation of the dentate gyrus induces Ca signals in astrocytes of region CA3, acting via a TTX-sensitive neuronal fiber projection that releases glutamate as its major neurotransmitter. Astrocyte Ca transients can occur within two seconds of the onset of neural stimulation, and waves and oscillations result from sustained stimulation at frequencies as low as 2 Hz. Neurally-evoked astrocyte Ca waves propagate both within and between individual hippocampal astrocytes at velocities of 10 - 20 um/sec, while the oscillations have periods of approximately 20 sec (at 21 °C).

scholarly journals Values Encoded in Orbitofrontal Cortex Are Causally Related to Economic Choices

2020 ◽  
Author(s):  
Sébastien Ballesta ◽  
Weikang Shi ◽  
Katherine E. Conen ◽  
Camillo Padoa-Schioppa
Keyword(s):  
Electrical Stimulation ◽  
Neuronal Activity ◽  
Orbitofrontal Cortex ◽  
Rhesus Monkeys ◽  
Fundamental Issue ◽  
High Current ◽  
Neural Processes ◽  
Economic Choices ◽  
The Brain

AbstractIt has long been hypothesized that economic choices rely on the assignment and comparison of subjective values. Indeed, when agents make decisions, neurons in orbitofrontal cortex encode the values of offered and chosen goods. Moreover, neuronal activity in this area suggests the formation of a decision. However, it is unclear whether these neural processes are causally related to choices. More generally, the evidence linking economic choices to value signals in the brain remains correlational. We address this fundamental issue using electrical stimulation in rhesus monkeys. We show that suitable currents bias choices by increasing the value of individual offers. Furthermore, high-current stimulation disrupts both the computation and the comparison of subjective values. These results demonstrate that values encoded in orbitofrontal cortex are causal to economic choices.

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