Kunjumon I Vadakkan

Publications (21) View all

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  Article: A structure-function mechanism for schizophrenia.

  Kunjumon I Vadakkan
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  ABSTRACT: THE MULTIPLE ETIOLOGIES OF SCHIZOPHRENIA PROMPT US TO RAISE THE QUESTION: what final common pathway can induce a convincing sense of the reality of the hallucinations in this disease? The observation that artificial stimulation of an intermediate order of neurons of a normal nervous system induces hallucinations indicates that the lateral entry of activity (not resulting from canonical synaptic transmission) at intermediate neuronal orders may provide a mechanism for hallucinations. Meaningful hallucinations can be de-constructed into an organized temporal sequence of internal sensations of associatively learned items that occur in the absence of any external stimuli. We hypothesize that these hallucinations are autonomously generated by the re-activation of pathological non-specific functional LINKs formed between the postsynaptic membranes at certain neuronal orders and are examined as a final common mechanism capable of explaining most of the features of the disease. Reversible and stabilizable hemi-fusion between simultaneously activated adjacent postsynaptic membranes is viewed as one of the normal mechanisms for functional LINK formation and is dependent on lipid membrane composition. Methods of removing the proteins that may traverse the non-specifically hemi-fused membrane segments and attempts to replace the phospholipid side chains to convert the membrane composition to a near-normal state may offer therapeutic opportunities.
  Frontiers in psychiatry / Frontiers Research Foundation. 01/2012; 3:108.
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  Article: A possible mechanism of transfer of memories from the hippocampus to the cortex.

  Kunjumon I Vadakkan
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  ABSTRACT: The mechanism of time-dependent transfer of memories from the hippocampus to the cortex associated with the memory consolidation process still remains unknown. By visualizing memory as the virtual sensation of sensory stimuli, it has become possible to conceptualize memory as an integral of semblances induced at the postsynapses in the absence of the activation of their corresponding presynapses. This is hypothesized to be possible during memory retrieval by the re-activation of functional LINKs formed between the postsynapses during learning. On occasions of repetition of learning, related learning and unrelated learning, stimulation of the sensory receptor pairs used in the original learning event activates new hippocampal neurons incorporated in the circuitry and induces formation of new functional LINKs in the cortex. Since the virtual sensory units of semblances provide provisions for the formation of similar net semblance from different sets of postsynapses of origin both independently and cumulatively, locations of their formation appear transferable. When semblances from the cortex alone become sufficient to contribute to a specific memory, after a certain period of time from the initial learning, removal of the hippocampus gives an impression of (an apparent) transfer of memories from the hippocampus to the cortex.
  Medical Hypotheses 05/2011; 77(2):234-43. · 1.39 Impact Factor
• Article: Identification of an adenylyl cyclase inhibitor for treating neuropathic and inflammatory pain.

  Hansen Wang, Hui Xu, Long-Jun Wu, Susan S Kim, Tao Chen, Kohei Koga, Giannina Descalzi, Bo Gong, Kunjumon I Vadakkan, Xuehan Zhang, Bong-Kiun Kaang, Min Zhuo
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  ABSTRACT: Neuropathic pain, often caused by nerve injury, is commonly observed among patients with different diseases. Because its basic mechanisms are poorly understood, effective medications are limited. Previous investigations of basic pain mechanisms and drug discovery efforts have focused mainly on early sensory neurons such as dorsal root ganglion and spinal dorsal horn neurons, and few synaptic-level studies or new drugs are designed to target the injury-related cortical plasticity that accompanies neuropathic pain. Our previous work has demonstrated that calcium-stimulated adenylyl cyclase 1 (AC1) is critical for nerve injury-induced synaptic changes in the anterior cingulate cortex. Through rational drug design and chemical screening, we have identified a lead candidate AC1 inhibitor, NB001, which is relatively selective for AC1 over other adenylate cyclase isoforms. Using a variety of behavioral tests and toxicity studies, we have found that NB001, when administered intraperitoneally or orally, has an analgesic effect in animal models of neuropathic pain, without any apparent side effects. Our study thus shows that AC1 could be a productive therapeutic target for neuropathic pain and describes a new agent for the possible treatment of neuropathic pain.
  Science translational medicine 01/2011; 3(65):65ra3. · 7.80 Impact Factor
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  Article: Processing Semblances Induced through Inter-Postsynaptic Functional LINKs, Presumed Biological Parallels of K-Lines Proposed for Building Artificial Intelligence.

  Kunjumon I Vadakkan
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  ABSTRACT: The internal sensation of memory, which is available only to the owner of an individual nervous system, is difficult to analyze for its basic elements of operation. We hypothesize that associative learning induces the formation of functional LINK between the postsynapses. During memory retrieval, the activation of either postsynapse re-activates the functional LINK evoking a semblance of sensory activity arriving at its opposite postsynapse, nature of which defines the basic unit of internal sensation - namely, the semblion. In neuronal networks that undergo continuous oscillatory activity at certain levels of their organization re-activation of functional LINKs is expected to induce semblions, enabling the system to continuously learn, self-organize, and demonstrate instantiation, features that can be utilized for developing artificial intelligence (AI). This paper also explains suitability of the inter-postsynaptic functional LINKs to meet the expectations of Minsky's K-lines, basic elements of a memory theory generated to develop AI and methods to replicate semblances outside the nervous system.
  Frontiers in Neuroengineering 01/2011; 4:8.
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  Article: Framework of Consciousness from Semblance of Activity at Functionally LINKed Postsynaptic Membranes.

  Kunjumon I Vadakkan
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  ABSTRACT: Consciousness is seen as a difficult "binding" problem. Binding, a process where different sensations evoked by an item are associated in the nervous system, can be viewed as a process similar to associative learning. Several reports that consciousness is associated with some form of memory imply that different forms of memories have a common feature contributing to consciousness. Based on a proposed synaptic mechanism capable of explaining different forms of memory, we developed a framework for consciousness. It is based on the formation of semblance of sensory stimulus from (1) synaptic semblances when excitatory postsynaptic potentials arrive at functionally LINKed postsynaptic membranes, and (2) network semblances when these potentials summate to elicit action potential initiating activity in a network of neurons. It is then possible to derive a framework for consciousness as a multi-dimensional semblance. According to this framework, a continuum of semblances formed from background sensory stimuli and oscillating neuronal activities serve to maintain consciousness. Feasibility of this framework to explain various physiological and pathological states of consciousness, its subjective nature and qualia is examined.
  Frontiers in psychology. 01/2010; 1:168.