Noninvasive remote activation of the ventral midbrain by transcranial direct current stimulation of prefrontal cortex

Abstract

The midbrain lies deep within the brain and has an important role in reward, motivation, movement and the pathophysiology of various neuropsychiatric disorders such as Parkinson's disease, schizophrenia, depression and addiction. To date, the primary means of acting on this region has been with pharmacological interventions or implanted electrodes. Here we introduce a new noninvasive brain stimulation technique that exploits the highly interconnected nature of the midbrain and prefrontal cortex to stimulate deep brain regions. Using transcranial direct current stimulation (tDCS) of the prefrontal cortex, we were able to remotely activate the interconnected midbrain and cause increases in participants' appraisals of facial attractiveness. Participants with more enhanced prefrontal/midbrain connectivity following stimulation exhibited greater increases in attractiveness ratings. These results illustrate that noninvasive direct stimulation of prefrontal cortex can induce neural activity in the distally connected midbrain, which directly effects behavior. Furthermore, these results suggest that this tDCS protocol could provide a promising approach to modulate midbrain functions that are disrupted in neuropsychiatric disorders.

Shaping Memory Accuracy by Left Prefrontal Transcranial Direct Current Stimulation

“…Although we aimed for a stimulation of the dlPFC, the size of the stimulating electrode (35 cm 2 ) and individual variations in anatomy do not rule out that adjacent areas of the left frontal cortex were also affected by the stimulation. Moreover, transsynaptic effects of tDCS involving connected brain areas have also been described (Lang et al, 2005;Chib et al, 2013). In particular, it is conceivable that tDCS may modulate the influence of the left dlPFC on remote brain regions (e.g., the medial temporal lobe) that are actually responsible for encoding episodic memories (Reber et al, 2002).…”

“…As initially documented in the motor system (Nitsche and Paulus, 2000), cathodal tDCS decreases and anodal stimulation increases, respectively, neuronal excitability and spontaneous firing rate by altering resting membrane potential. This technique has since been widely used to explore brain network dynamics and organization (Dayan et al, 2013), particularly concerning cognition (Kuo and Nitsche, 2012) and memory (Brasil-Neto, 2012). Moreover, tDCS enables to enhance adaptive and to ameliorate maladaptive neuroplastic processes with potentially therapeutic effects on various neuropsychiatric disorders (Kuo et al, 2014).…”

Transcranial Direct Current Stimulation (tDCS) of the Anterior Prefrontal Cortex (aPFC) Modulates Reinforcement Learning and Decision-Making Under Uncertainty: a Double-Blind Crossover Study

“…In the present study, tDCS was applied over the aPFC (Karim et al 2010;Chib et al 2013;Manuel et al 2014) during a probabilistic reinforcement learning task (Frank et al 2004;Frank 2005;Wheeler and Fellows 2008) with the aim to investigate the causal role of this area in (1) probabilistic reinforcement learning, (2) trial-by-trial behavioral adaptation in response to positive/negative feedback, and (3) decision-making under uncertainty.…”

A Estimulação Transcraniana Por Corrente Contínua No Tratamento Da Doença De Parkinson

“…A ETCC usa uma corrente elétrica direta de baixa intensidade que é entregue por dois eletrodos de superfície, produzindo um deslocamento de excitabilidade, induzida por uma mudança de potencial de membrana [2]. Nesse contexto, a ETCC surge como possível ferramenta terapêutica, que já mostrou resultados em doenças como fibromialgia e depressão, além de auxiliar na reabilitação motora, e assim, pode apresentar efeitos benéficos na DP [3].A doença de Parkinson (DP) é uma doença neurodegenerativa que afeta cerca de 1% da população acima dos 60 anos e 5%, acima dos 85. É a segunda doença neurodegenerativa mais prevalente no mundo e também a segunda forma mais prevalente de distúrbio do movimento.…”

“…Estima-se que cinco milhões de pessoas no mundo sejam afetadas por essa condição (50 a 260 casos a cada 100.000 indivíduos). A transição demográfica e envelhecimento populacional sugerem um consequente aumento em sua incidência e prevalência no futuro, inclusive no Brasil [3].Sendo assim, fica expressa a necessidade do desenvolvimento de novas ferramentas terapêuticas que sejam menos dispendiosas que as opções atuais, visto que a DP é caracterizada pela perda progressiva de neurônios dopaminérgicos na substância negra [4], gerando uma disfunção incapacitante tanto motora quanto cognitiva, podendo levar a incapacidade extrema como a imobilidade [5]. …”