Steve Ramirez

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Steve Ramirez (born 1988) is a neuroscientist whose professional career centers around the manipulation of the brain's physical properties. [1] [2] Through his work, Ramirez aims to find methods of relief for symptoms of mental health disorders through the use of optogenetics. [3] [4]

Contents

Ramirez graduated from MIT in 2010 and later earned his Ph.D. in neuroscience for his work on memories in the lab of Susumu Tonegawa. [5] [6]

Early life

Ramirez was born in Massachusetts to Salvadoran immigrants and grew up in Everett, Massachusetts. His parents, older brother, and sister escaped wartime El Salvador towards the end of the 1970s and came to the United States. [2] In his early teens, Ramirez's cousin experienced atrophy and coma during childbirth, which influenced Ramirez's curiosity on the topic of neuroscience, and the ability to physically manipulate brain chemistry. [1] He later attended high school in Massachusetts.

Ramirez attended college at Boston University in Massachusetts where he was trying to find an academic field that suited him. His girlfriend at the time suggested to Ramirez that he should seek guidance from the head of department of the neuroscience program at Boston University. Ramirez agreed, and began to be mentored by the head of department, where he developed a passion for the field of work and found a community among the members of the program. When Ramirez and his girlfriend broke up, he was inspired to see if he could change the feelings behind those memories while keeping the memory intact. [7] [5]

Throughout the rest of his education, Ramirez decided to focus his studies on the neuroscience of memory, which began the path of his career and achievements. [5] After graduating from college in 2010, Ramirez joined the lab of Susumu Tonegawa where he continued his studies, and eventually earned his Ph.D. in neuroscience. Ramirez's earliest scientific work occurred with the help of his mentor, Xu Liu, who Ramirez attributes much of his achievements to, and claims that Liu taught him many skills necessary for their work. [2]

Career

Steve Ramirez is known for his studies on memory where he went on to publish six research articles under Tonegawa Susumu's lab. [8] [9] [10] [11] [12] [13] In 2013, Ramirez collaborated with the Massachusetts Institute of Technology (MIT), which studied how false memories can be formed in the hippocampus. [14] Ramirez and Liu also gave a TED Talk in which they discussed their research. Ramirez expressed how he was manipulating the brain cells of mice to respond to pulses of light and manipulate their memories. He was aiming to make this process accessible to humans as well to treat mental illness. [7]

Awards

Selected publications

  1. [8]
  2. [10]
  3. [9]
  4. [11]
  5. [12]
  6. [13]

Related Research Articles

<span class="mw-page-title-main">Hippocampus</span> Vertebrate brain region involved in memory consolidation

The hippocampus, also hippocampus proper, is a major component of the brain of humans and many other vertebrates. In the human brain the hippocampus, the dentate gyrus, and the subiculum are the components of the hippocampal formation located in the limbic system. The hippocampus plays important roles in the consolidation of information from short-term memory to long-term memory, and in spatial memory that enables navigation. In humans, and other primates the hippocampus is located in the archicortex, one of the three regions of allocortex, in each hemisphere with neural projections to the neocortex. The hippocampus, as the medial pallium, is a structure found in all vertebrates.

<span class="mw-page-title-main">Long-term potentiation</span> Persistent strengthening of synapses based on recent patterns of activity

In neuroscience, long-term potentiation (LTP) is a persistent strengthening of synapses based on recent patterns of activity. These are patterns of synaptic activity that produce a long-lasting increase in signal transmission between two neurons. The opposite of LTP is long-term depression, which produces a long-lasting decrease in synaptic strength.

<span class="mw-page-title-main">Dentate gyrus</span> Region of the hippocampus in the brain

The dentate gyrus (DG) is one of the subfields of the hippocampus, in the hippocampal formation. The hippocampal formation is located in the temporal lobe of the brain, and includes the hippocampus subfields, and other subfields including the dentate gyrus, subiculum, and presubiculum.

<span class="mw-page-title-main">Fear conditioning</span> Behavioral paradigm in which organisms learn to predict aversive events

Pavlovian fear conditioning is a behavioral paradigm in which organisms learn to predict aversive events. It is a form of learning in which an aversive stimulus is associated with a particular neutral context or neutral stimulus, resulting in the expression of fear responses to the originally neutral stimulus or context. This can be done by pairing the neutral stimulus with an aversive stimulus. Eventually, the neutral stimulus alone can elicit the state of fear. In the vocabulary of classical conditioning, the neutral stimulus or context is the "conditional stimulus" (CS), the aversive stimulus is the "unconditional stimulus" (US), and the fear is the "conditional response" (CR).

An engram is a unit of cognitive information imprinted in a physical substance, theorized to be the means by which memories are stored as biophysical or biochemical changes in the brain or other biological tissue, in response to external stimuli.

<span class="mw-page-title-main">Adult neurogenesis</span> Generating of neurons from neural stem cells in adults

Adult neurogenesis is the process in which neurons are generated from neural stem cells in the adult. This process differs from prenatal neurogenesis.

<span class="mw-page-title-main">Place cell</span> Place-activated hippocampus cells found in some mammals

A place cell is a kind of pyramidal neuron in the hippocampus that becomes active when an animal enters a particular place in its environment, which is known as the place field. Place cells are thought to act collectively as a cognitive representation of a specific location in space, known as a cognitive map. Place cells work with other types of neurons in the hippocampus and surrounding regions to perform this kind of spatial processing. They have been found in a variety of animals, including rodents, bats, monkeys and humans.

<span class="mw-page-title-main">Susumu Tonegawa</span> Japanese scientist (born 1939)

Susumu Tonegawa is a Japanese scientist who was the sole recipient of the Nobel Prize for Physiology or Medicine in 1987 for his discovery of V(D)J recombination, the genetic mechanism which produces antibody diversity. Although he won the Nobel Prize for his work in immunology, Tonegawa is a molecular biologist by training and he again changed fields following his Nobel Prize win; he now studies neuroscience, examining the molecular, cellular and neuronal basis of memory formation and retrieval.

<span class="mw-page-title-main">Septal area</span> Area in the lower, posterior part of the medial surface of the frontal lobe

The septal area, consisting of the lateral septum and medial septum, is an area in the lower, posterior part of the medial surface of the frontal lobe, and refers to the nearby septum pellucidum.

Ca<sup>2+</sup>/calmodulin-dependent protein kinase II Class of enzymes

Ca2+
/calmodulin-dependent protein kinase II is a serine/threonine-specific protein kinase that is regulated by the Ca2+
/calmodulin complex. CaMKII is involved in many signaling cascades and is thought to be an important mediator of learning and memory. CaMKII is also necessary for Ca2+
 homeostasis and reuptake in cardiomyocytes, chloride transport in epithelia, positive T-cell selection, and CD8 T-cell activation.

<span class="mw-page-title-main">Hippocampus anatomy</span> Component of brain anatomy

Hippocampus anatomy describes the physical aspects and properties of the hippocampus, a neural structure in the medial temporal lobe of the brain. It has a distinctive, curved shape that has been likened to the sea-horse monster of Greek mythology and the ram's horns of Amun in Egyptian mythology. This general layout holds across the full range of mammalian species, from hedgehog to human, although the details vary. For example, in the rat, the two hippocampi look similar to a pair of bananas, joined at the stems. In the human and other primates, the portion of the hippocampus near the base of the temporal lobe is much broader than the part at the top. Due to the three-dimensional curvature of this structure, two-dimensional sections such as shown are commonly seen. Neuroimaging pictures can show a number of different shapes, depending on the angle and location of the cut.

Memory consolidation is a category of processes that stabilize a memory trace after its initial acquisition. A memory trace is a change in the nervous system caused by memorizing something. Consolidation is distinguished into two specific processes. The first, synaptic consolidation, which is thought to correspond to late-phase long-term potentiation, occurs on a small scale in the synaptic connections and neural circuits within the first few hours after learning. The second process is systems consolidation, occurring on a much larger scale in the brain, rendering hippocampus-dependent memories independent of the hippocampus over a period of weeks to years. Recently, a third process has become the focus of research, reconsolidation, in which previously consolidated memories can be made labile again through reactivation of the memory trace.

<span class="mw-page-title-main">Nucleus reuniens</span>

The nucleus reuniens is a region of the thalamic midline nuclear group. In the human brain, it is located in the interthalamic adhesion. It is also known as the medioventral nucleus.

<span class="mw-page-title-main">Alcino J. Silva</span> American neuroscientist (born 1961)

Alcino J. Silva is a Portuguese-American neuroscientist who was the recipient of the 2008 Order of Prince Henry and elected as a fellow of the American Association for the Advancement of Science in 2013 for his contributions to the molecular cellular cognition of memory, a field he pioneered with the publication of two articles in Science in 1992.

<span class="mw-page-title-main">TetTag</span> Mouse line used in memory research

The TetTag mouse is a bi-transgenic mutant used in neuroscience research that expresses a persistent marker under control of the immediate early gene fos. This mouse strain allows the stable labeling of activated neurons in mice in a defined time window of several hours.

<span class="mw-page-title-main">Sharp waves and ripples</span> Biological phenomenon

Sharp waves and ripples (SPW-R), also called sharp wave ripples (SWR), are oscillatory patterns produced by extremely synchronized activity of neurons in the mammalian hippocampus and neighboring regions which occur spontaneously in idle waking states or during NREM sleep. They can be observed with a variety of electrophysiological methods such as field recordings or EEG. They are composed of large amplitude sharp waves in local field potential and produced by thousands of neurons firing together within a 30–100 ms window. Within this broad time window, pyramidal cells fire only at specific times set by fast spiking GABAergic interneurons. The fast rhythm of inhibition synchronizes the firing of active pyramidal cells, each of which only fires one or two action potentials exactly between the inhibitory peaks, collectively generating the ripple pattern. SWRs have been extensively characterized by György Buzsáki and have been shown to be involved in memory consolidation in NREM sleep. Neuronal firing sequences acquired during wakefulness are replayed during SWRs.

<span class="mw-page-title-main">John O'Keefe (neuroscientist)</span> American–British neuroscientist

John O'Keefe is an American-British neuroscientist, psychologist and a professor at University College London.

Hippocampal replay is a phenomenon observed in rats, mice, cats, rabbits, songbirds and monkeys. During sleep or awake rest, replay refers to the re-occurrence of a sequence of cell activations that also occurred during activity, but the replay has a much faster time scale. It may be in the same order, or in reverse. Cases were also found where a sequence of activations occurs before the actual activity, but it is still the same sequence. This is called preplay.

Neal J. Cohen is a professor of psychology in the Cognitive Neuroscience division of the University of Illinois at Urbana–Champaign. He is appointed as a full-time faculty member in the Beckman Institute for Advanced Science and Technology at the University of Illinois. He is the founding director of the Center for Nutrition, Learning, and Memory (CNLM), a partnership of the University of Illinois and Abbott Laboratories as of 2011. He is also the founding director of the Interdisciplinary Health Sciences Initiative (IHSI) at the University of Illinois, formed 2014.

Christine Denny is an American neuroscientist and associate professor of Clinical Neurobiology in Psychiatry in the Department of Psychiatry at Columbia University Irving Medical Center in New York City. Denny investigates the molecular mechanisms underlying learning and memory. She developed a novel technique to label neurons that encode specific memories. She used this technique to probe what happens to hippocampal memory traces in different disease states.

References

  1. 1 2 "Steve Ramirez". MIT Technology Review. Retrieved 2023-11-07.
  2. 1 2 3 "The 30 Top Thinkers Under 30: Steve Ramirez, 26, Neuroscience". Pacific Standard. Retrieved 2023-11-06.
  3. ↑ "Steve Ramirez". explorer-directory.nationalgeographic.org. Retrieved 2023-11-06.
  4. ↑ "Steve Ramirez, Ph.D." Steve Ramirez, Ph.D. | Brain & Behavior Research Foundation. 2023-05-20. Retrieved 2023-11-09.
  5. 1 2 3 "Steve Ramirez Reshapes Memories in the Brains of Mice". The Scientist Magazine®. Retrieved 2023-11-06.
  6. ↑ "Emerging Scholar Profile: Ramirez Finds That Relationships Remain Key in Psychological and Brain Sciences". Diverse: Issues In Higher Education. 2018-02-04. Retrieved 2023-11-09.
  7. 1 2 "Steve Ramirez: If We Could Erase Memories ... Should We?". TED RADIO HOUR. NPR. October 13, 2017.
  8. 1 2 Liu, X.; Ramirez, S.; Pang, P. T.; Puryear, C. B.; Govindarajan, A.; Deisseroth, K.; Tonegawa, S. (2012). "Optogenetic stimulation of a hippocampal engram activates fear memory recall". Nature. 484 (7394): 381–385. doi:10.1038/nature11028. PMC   3331914 . PMID   22441246.
  9. 1 2 Redondo, R. L.; Kim, J.; Arons, A. L.; Ramirez, S.; Liu, X.; Tonegawa, S. (2014). "Bidirectional switch of the valence associated with a hippocampal contextual memory engram". Nature. 513 (7518): 426–430. doi:10.1038/nature13725. PMC   4169316 . PMID   25162525.
  10. 1 2 Ramirez, S.; Liu, X.; Lin, P. A.; Suh, J.; Pignatelli, M.; Redondo, R. L.; Ryan, T. J.; Tonegawa, S. (2013). "Creating a false memory in the hippocampus". Science. 341 (6144): 387–391. doi:10.1126/science.1239073. hdl: 1721.1/85964 . PMID   23888038.
  11. 1 2 Ramirez, S.; Liu, X.; MacDonald, C. J.; Moffa, A.; Zhou, J.; Redondo, R. L.; Tonegawa, S. (2015). "Activating positive memory engrams suppresses depression-like behaviour". Nature. 522 (7556): 335–339. doi:10.1038/nature14514. PMC   5583720 . PMID   26085274.
  12. 1 2 Ramirez, S. (2018). "Crystallizing a memory". Science. 360 (6394): 1182–1183. doi:10.1126/science.aau0043. PMID   29903960.
  13. 1 2 Shpokayte, M.; McKissick, O.; Guan, X.; Yuan, B.; Rahsepar, B.; Fernandez, F. R.; Ruesch, E.; Grella, S. L.; White, J. A.; Liu, X. S.; Ramirez, S. (2022). "Hippocampal cells segregate positive and negative engrams". Communications Biology. 5 (1): 1009. doi:10.1038/s42003-022-03906-8. PMC   9512908 . PMID   36163262.
  14. ↑ Ramirez, Steve; Liu, Xu; Lin, Pei-Ann; Suh, Junghyup; Pignatelli, Michele; Redondo, Roger L.; Ryan, Tomás J.; Tonegawa, Susumu (2013-07-26). "Creating a False Memory in the Hippocampus". Science. 341 (6144): 387–391. doi:10.1126/science.1239073. ISSN   0036-8075.
  15. ↑ "Xu Liu and Steve Ramirez win 2014 American Ingenuity Award". MIT News | Massachusetts Institute of Technology. 2014-10-27. Retrieved 2023-10-26.
  16. ↑ "Steve Ramirez". explorer-directory.nationalgeographic.org. Retrieved 2023-10-26.
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