Neuroscience adalah ilmu yang mempelajari cara kerja otak manusia dan merupakan ilmu masa depan dengan berbagai aplikasi luas. Jurusan Neuroscience mempelajari anatomi, fisiologi, biokimia, dan molekuler otak serta psikologi dan ilmu berpikir. Indonesia perlu mengembangkan neurosains untuk kesejahteraan masyarakat dengan pusat penelitian, kerja sama universitas, dan society neurosains. Dr. Taruna Ikrar dikenal sebag
Sekecil apapun operasi di dalam otak, tetap dapat membahayakan
Keselamatan tindakan anestesi untuk bedah saraf tergantung neuroanestesiologisnya
Tim Khusus: Dengan dedikasi ada kualitas, dengan komitmen ada keunggulan dan dengan jumlah ada pengalaman
Sistem koordinasi adalah sistem organ yang saling bekerja sama secara efisien untuk melakukan fungsi tertentu. Sistem koordinasi terdiri dari sistem saraf, sistem indera, dan sistem hormon.
A disinhibitory microcircuit initiates critical period plasticity in the visu...Taruna Ikrar
Earlysensoryexperienceinstructsthematurationofneuralcircuitry in the cortex1,2. This has been studied extensively in the primary visualcortex,inwhichlossofvisiontooneeyepermanentlydegrades corticalresponsivenesstothateye3,4,aphenomenonknownasocular dominance plasticity (ODP). Cortical inhibition mediates this process4–6,butthepreciseroleofspecificclassesofinhibitoryneurons in ODP is controversial. Here we report that evoked firing rates of binocular excitatory neurons in the primary visual cortex immediatelydropbyhalfwhenvisionisrestrictedtooneeye,butgradually return to normal over the followingtwenty-four hours, despite the fact that vision remains restricted to one eye. This restoration of binocular-like excitatory firing rates after monocular deprivation resultsfromarapid,althoughtransient,reductioninthefiringrates of fast-spiking, parvalbumin-positive (PV) interneurons, which in turncanbeattributedtoadecreaseinlocalexcitatorycircuitinput onto PV interneurons.This reduction in PV-cell-evoked responses after monocular lid suture is restricted to the critical period for ODPandappearstobenecessaryforsubsequentshiftsinexcitatory ODP. Pharmacologically enhancing inhibition at the time of sight deprivation blocks ODP and, conversely, pharmacogenetic reduction of PV cell firing rates can extend the critical period for ODP. Thesefindingsdefinethemicrocircuitchangesinitiatingcompetitive
plasticityduringcriticalperiodsofcorticaldevelopment.Moreover, they show that the restoration of evoked firing rates of layer 2/3 pyramidal neurons by PV-specific disinhibition is a key step in the progression of ODP.
An inhibitory pull–push circuit in frontal cortexTaruna Ikrar
Push–pull is a canonical computation of excitatory cortical circuits. By contrast, we identify a pull–push inhibitory circuit in frontal cortex that originates in vasoactive intestinal polypeptide (VIP)-expressing interneurons. During arousal, VIP cells rapidly and directly inhibit pyramidal neurons; VIP cells also indirectly excite these pyramidal neurons via parallel disinhibition. Thus, arousal exerts a feedback pull–push influence on excitatory neurons—an inversion of the canonical push–pull of feedforward input.
Pten and eph b4 regulate the establishment of perisomatic inhibition in mouse...Taruna Ikrar
Perisomatic inhibition of pyramidal neurons is established by fast-spiking, parvalbuminexpressing interneurons (PV cells). Failure to assemble adequate perisomatic inhibition is thought to underlie the aetiology of neurological dysfunction in seizures, autism spectrum disorders and schizophrenia. Here we show that in mouse visual cortex, strong perisomatic inhibition does not develop if PV cells lack a single copy of Pten. PTEN signalling appears to drive the assembly of perisomatic inhibition in an experience-dependent manner by suppressing the expression of EphB4; PVcells hemizygous for Pten show an B2-fold increase in expression of EphB4, and over-expression of EphB4 in adult PV cells causes a dismantling of perisomatic inhibition. These findings implicate a molecular disinhibitory mechanism driving the establishment of perisomatic inhibition whereby visual experience enhances Pten signalling, resulting in the suppression of EphB4 expression; this relieves a native synaptic repulsion between PV cells and pyramidal neurons, thereby promoting the assembly of perisomatic inhibition.
Abstract In the mammalian neocortex, excitatory neurons provide excitation in both columnar and laminar dimensions, which is modulated further by inhibitory neurons. However, our understanding of intracortical excitatory and inhibitory synaptic inputs in relation to principal excitatory neurons remains incomplete, and it is unclear how local excitatory and inhibitory synaptic connections to excitatory neurons are spatially organized on a layer-by-layer basis. In the present study, we combined whole cell recordings with laser scanning photostimulation via glutamate uncaging to map excitatory and inhibitory synaptic inputs to single excitatory neurons throughout cortical layers 2/3–6 in the mouse primary visual cortex (V1). We find that synaptic input sources of excitatory neurons span the radial columns of laminar microcircuits, and excitatory neurons in different V1 laminae exhibit distinct patterns of layer-specific organizationofexcitatoryinputs.Remarkably,thespatialextentofinhibitoryinputsofexcitatory neurons for a given layer closely mirrors that of their excitatory input sources, indicating that excitatory and inhibitory synaptic connectivity is spatially balanced across excitatory neuronal networks. Strong interlaminar inhibitory inputs are found, particularly for excitatory neurons in layers 2/3 and 5. This differs from earlier studies reporting that inhibitory cortical connections to excitatory neurons are generally localized within the same cortical layer. On the basis of the functional mapping assays, we conducted a quantitative assessment of both excitatory and inhibitory synaptic laminar connections to excitatory cells at single cell resolution, establishing precise layer-by-layer synaptic wiring diagrams of excitatory neurons in the visual cortex.
A characteristic of the developing mammalian visual system is a brief interval of plasticity, termed the “critical period,” when the circuitry of
primary visual cortex is most sensitive to perturbation of visual experience. Depriving one eye of vision (monocular deprivation [MD]) during
the critical period alters ocular dominance (OD) by shifting the responsiveness of neurons in visual cortex to favor the nondeprived eye. A
disinhibitory microcircuit involving parvalbumin-expressing (PV) interneurons initiates this OD plasticity. The gene encoding the neuronal
nogo-66-receptor1(ngr1/rtn4r) is required to close the critical period.Herewecombinedmousegenetics, electrophysiology,andcircuitmapping
with laser-scanning photostimulation to investigate whether disinhibition is confined to the critical period by ngr1.We demonstrate that ngr1
mutant mice retain plasticity characteristic of the critical period as adults, and that ngr1 operates within PV interneurons to restrict the loss of
intracortical excitatory synaptic input following MD in adult mice, and this disinhibition induces a “lower PV network configuration” in both
critical-period wild-type miceandadult ngr1/mice.Wepropose that ngr1 limits disinhibition to close the critical period forODplasticityand
that a decrease in PV expression levels reports the diminished recent cumulative activity of these interneurons.
A disinhibitory microcircuit initiates critical period plasticity in the visu...Taruna Ikrar
Early sensory experience instructs the maturation of neural circuitry in the cortex1, 2. This has been studied extensively in the primary visual cortex, in which loss of vision to one eye permanently degrades cortical responsiveness to that eye3, 4, a phenomenon known as ocular dominance plasticity (ODP). Cortical inhibition mediates this process4, 5, 6, but the precise role of specific classes of inhibitory neurons in ODP is controversial. Here we report that evoked firing rates of binocular excitatory neurons in the primary visual cortex immediately drop by half when vision is restricted to one eye, but gradually return to normal over the following twenty-four hours, despite the fact that vision remains restricted to one eye. This restoration of binocular-like excitatory firing rates after monocular deprivation results from a rapid, although transient, reduction in the firing rates of fast-spiking, parvalbumin-positive (PV) interneurons, which in turn can be attributed to a decrease in local excitatory circuit input onto PV interneurons. This reduction in PV-cell-evoked responses after monocular lid suture is restricted to the critical period for ODP and appears to be necessary for subsequent shifts in excitatory ODP. Pharmacologically enhancing inhibition at the time of sight deprivation blocks ODP and, conversely, pharmacogenetic reduction of PV cell firing rates can extend the critical period for ODP. These findings define the microcircuit changes initiating competitive plasticity during critical periods of cortical development. Moreover, they show that the restoration of evoked firing rates of layer 2/3 pyramidal neurons by PV-specific disinhibition is a key step in the progression of ODP.
1. SURYA NEWSLETTER
No. 01/Nov/2012 Advancing Science & Technology, Fostering Innovation Bidang Ilmu : Neuroscience
Apa itu Neuroscience?
FENOMENA KEAJAIBAN OTAK MANUSIA &
Neuroscience adalah ilmu masa depan KEBANGKITAN NEUROSAINS INDONESIA
(ultimate science), ilmu yang tingkat
Dewasa ini telah muncul dan berkembang satu cabang ilmu pengetahuan baru yang disebut
kerumitannya sangat menantang dan
sebagai neurosains. Ilmu ini berusaha untuk memahami perilaku manusia dengan mencoba
menarik karena menyangkut otak yang
menganalisis unsur-unsur biologisnya. Misteri utama di dalam ilmu neurosains adalah segala
menjadi pusat kehidupan. Ilmu ini
sesuatu terkait dengan otak manusia, serta kaitannya dengan kesadaran sebagai unsur utama
mempunyai aplikasi sangat luas dari mulai
pembentuk identitas manusia. Di dalam pikiran para ilmuwan neurosains, misteri dualisme
marketing (neuro marketing), web design (neuro
manusia (tubuh dan jiwa) menjadi perhatian yang sangat menarik.
web design), sampai ke medis (neurologist).
Otak merupakan permata dari mahkota tubuh manusia. Dengan kekuatan dan keajaiban otak,
manusia bisa menemukan berbagai hal yang dapat kita nikmati dewasa ini. Penemuan tersebut,
Apa yang dipelajari mulai tingkat molekuler atau atom, pengobatan berbagai penyakit, penemuan berbagai teknologi
di jurusan Neuroscience? canggih, hingga kemampuan manusia menembus tata surya bahkan di masa depan galaksi. Itu
Jurusan Neuroscience mempelajari cara kerja semua karena peran dari keajaiban otak manusia, sebagai pusat intelejen, berpikir, berkesadaran,
otak, seperti anatomi (bentuk dan struktur berinovasi, juga atas fungsi otak sebagai pusat penerjemah panca indra kita. Bahkan semua
otak), fisiologi (fungsi bagian-bagian otak), sistem organ kita (seperti: jantung, paru-paru, hati, usus, ginjal, dan lain sebagainya) berada
biochemistry (sifat kimia dan reaksi kimia dalam kontrol dan regulasi sistem otak.
dalam otak), molecular biology (molekul Para ahli di dunia, dari berbagai negara telah mengembangkan dan mendorong kemajuan
atau protein yang membentuk otak) neurosains begitu pesatnya. Kemajuan yang dipimpin oleh ilmuwan-ilmuwan Amerika Serikat,
ditambah dengan ilmu Psikologi (kelakuan Jerman, Jepang dan negara-negara maju di dunia yang terhimpun di dalam organisasi
dan emosi) dan Cognitive Science (ilmu internasional Society for Neurosciences (SFN), telah menjadikan neurosains menjadi ilmu moderen
tentang proses berfikir). dan ilmu masa depan, yang secara nyata bisa berimplikasi sangat luas terhadap kehidupan umat
manusia. Menyadari hal tersebut diatas, Indonesia sudah seharusnya, menfokuskan perhatian
Update Info tentang Neuroscience besar terhadap pengembangan, dan kemajuan neurosains di tanah air, demi kemaslahatan
masyarakat Indonesia. Usaha tersebut dapat dilakukan dalam bentuk mengembangkan
The Human-Body-Brain-Power
pusat-pusat penelitian, kerjasama antara universitas dalam dan luar negeri, hingga tahap
http://medicals.multiply.com/video/item/79
pembentukan Center of Excellent of Neurosciences, pembentukan Brain Research and Brain Services
/The-Human-Body-Brain-Power/
Center, serta tentu saja dibutuhkan pembentukan society atau komunitas neurosains Indonesia.
Faculty for Undergraduate Neuroscience
Dengan langka tersebut, akan menjadi awal yang baik bagi kemajuan dan kebangkitan neurosains
http://www.funjournal.org/
di Indonesia.
Nama Doktor Taruna Ikrar tidak lagi asing di dunia kedokteran internasional. Beliau merupakan seorang
pakar di bidang farmakologi, penyakit jantung, dan saraf. Pria yang menyelesaikan program post-doctoral
bidang neurosains di School of Medicine, University of California, Amerika Serikat tahun 2009, dan sejak itu
telah dipromosikan sebagai Staf Akademik, dengan posisi senior/leader scientist dan dokter spesialis di UC
Irvine, merupakan penemu teknik terbaru pengobatan penyakit epilepsy yang selama ini dianggap tak
tersembuhkan. Teknik ini dikenal sebagai gene therapy.
Doktor kelahiran 15 April 1969 ini juga merupakan pemegang paten metode pemetaan otak manusia sejak
tahun 2009. Metode ini berhasil menggambarkan dinamika yang terjadi pada otak manusia dengan rinci.
Ilmuwan Indonesia asal Makassar ini memang banyak menempuh pendidikannya di luar negeri. Sebut saja,
Universitas Niigata, Jepang, tempat ia menamatkan studi doktoral di bidang ilmu penyakit jantung, dan
Bologna University, Italy tempat dia melanjutkan advance medical training untuk pengobatan gangguan
Arrhythmias Jantung dan operasi pemasangan pacemaker (ICD). Namun, kecintaannya dan keinginannya
memajukan bidang kedokteran khususnya neurosains di Indonesia memanggilnya pulang ke tanah air dan
menjadi pengajar di Surya University.
Doktor yang memiliki lebih dari 40 publikasi jurnal internasional ini pernah menjabat sebagai Wakil Ketua PB
DR. TARUNA IKRAR, MD., PH.D Ikatan Dokter Indonesia periode 2000-2003. Selain itu, ia juga menjadi anggota American Cardiology Collage,
Dosen Surya University, Head of Neuroscience Center of
and Society for Neurosciences, International Heart Research Association, Asia Pacific Hearth Rhythm Association,
Surya University, Penemu metode baru penyembuhan
epilepsi & pemetaan otak dan Japanese Cardiologist Association. Walau sibuk, suami dari Dr. Elfi Wardaningsih, Ph.D. ini masih
menyempatkan diri untuk berenang dan bermain dengan kedua buah hatinya.