Mystery at the heart of life

_{News
December 21, 2014

Cell biology, Intelligent Design, News

1}_{Categories
Cell biology
Intelligent Design
News}

Share: Facebook; Twitter/X; LinkedIn; Flipboard; Print; Email

By Biologic Institute’s Ann Gauger, at Christianity Today’s Behemoth, the secret life of cells:

Our bodies are made up of some 100 trillion cells. We tend to think of cells as static, because that’s how they were presented to us in textbooks. In fact, the cell is like the most antic, madcap, crowded (yet fantastically efficient) city you can picture. And at its heart lies a mystery—or I should say, several mysteries—involving three special kinds of molecules: DNA, RNA, and proteins.

These molecules are assembled into long chains called polymers, and are uniquely suited for the roles they play. More importantly, life absolutely depends upon them. We have to have DNA, RNA, and protein all present and active at the same time for a living organism to live.

How they work together so optimally and efficiently is not merely amazing, but also a great enigma, a mystery that lies at the heart of life itself. More. Paywall soon after. May be worth it.

Follow UD News at Twitter!

Comments

The next step following on from this work is to find out how the braking mechanism forms in young animals. Future studies will also focus on understanding the precise role the booster circuit plays in early brain development.
An excitatory cortical feedback loop gates retinal wave transmission in rodent thalamus Yasunobu Murata and Matthew T Colonnese eLife. 5: e18816. doi: 10.7554/eLife.18816

Work in progress... stay tuned. Complex complexity.Dionisio_{February 13, 2017
February
02
Feb
13
13
2017
03:16 PM
3
03
16
PM
PDT}

The brain of a developing fetus has a big job to do: it needs to create the important connections between neurons that the individual will need later in life. This is a challenge because the first connections that form between neurons are sparse, weak and unreliable. They would not be expected to be able to transmit signals in a robust or effective way, and yet they do. How the nervous system solves this problem is an important question [...]
An excitatory cortical feedback loop gates retinal wave transmission in rodent thalamus Yasunobu Murata and Matthew T Colonnese eLife. 5: e18816. doi: 10.7554/eLife.18816

Complex complexity.Dionisio_{February 13, 2017
February
02
Feb
13
13
2017
03:12 PM
3
03
12
PM
PDT}

Spontaneous retinal waves are critical for the development of receptive fields in visual thalamus (LGN) and cortex (VC). [...] whether central circuit specializations also exist to control their propagation through visual pathways of the brain is unknown. [...] the early retino-thalamo-cortical circuit uses developmentally specialized feedback amplification to ensure powerful, high-fidelity transmission of retinal activity despite immature connectivity.
An excitatory cortical feedback loop gates retinal wave transmission in rodent thalamus Yasunobu Murata and Matthew T Colonnese eLife. 5: e18816. doi: 10.7554/eLife.18816

Complex complexity.Dionisio_{February 13, 2017
February
02
Feb
13
13
2017
03:08 PM
3
03
08
PM
PDT}

Neuronal activity has been shown to be essential for the proper formation of neuronal circuits, affecting developmental processes like neurogenesis, migration, programmed cell death, cellular differentiation, formation of local and long-range axonal connections, synaptic plasticity or myelination. Accordingly, neocortical areas reveal distinct spontaneous and sensory-driven neuronal activity patterns already at early phases of development. [...] spontaneous activity patterns become more complex, involve larger networks and propagate over several neocortical areas. [...] a number of key questions remain to be addressed in the near future: [...]
Spontaneous Neuronal Activity in Developing Neocortical Networks: From Single Cells to Large-Scale Interactions Heiko J. Luhmann, Anne Sinning, Jenq-Wei Yang, Vicente Reyes-Puerta, Maik C. Stüttgen, Sergei Kirischuk and Werner Kilb Front Neural Circuits. 10: 40. doi: 10.3389/fncir.2016.00040

Complex complexity.Dionisio_{February 13, 2017
February
02
Feb
13
13
2017
02:47 PM
2
02
47
PM
PDT}

Infancy, childhood, and adolescence are times of dramatic change in the brain, characterized by widespread synaptogenesis, myelination, and synaptic pruning. During these years, spindle amplitude, duration, density, frequency, and topology change. [...] sleep spindles change over the course of a lifetime, in parallel with the multitude of changes in the developing and aging brain. Spindles may serve different functions throughout the lifespan. Future studies focused on age-specific brain anatomical and functional differences will ultimately help us understand these functions.
Form and Function of Sleep Spindles across the Lifespan. Clawson BC, Durkin J, Aton SJ Neural Plast. 2016:6936381. doi: 10.1155/2016/6936381.

Complex complexity.Dionisio_{February 12, 2017
February
02
Feb
12
12
2017
06:46 PM
6
06
46
PM
PDT}

[...] a major gap in our knowledge remains with regard to causality. We currently do not know for certain whether (and how) network activity in wakefulness promotes local spindle activity. Neither do we know whether (and how) global and local spindles contribute to thalamocortical network plasticity and cognitive functions associated with this plasticity.
Form and Function of Sleep Spindles across the Lifespan. Clawson BC, Durkin J, Aton SJ Neural Plast. 2016:6936381. doi: 10.1155/2016/6936381.

Complex complexity.Dionisio_{February 12, 2017
February
02
Feb
12
12
2017
06:36 PM
6
06
36
PM
PDT}

Since the advent of EEG recordings, sleep spindles have been identified as hallmarks of non-REM sleep. Despite a broad general understanding of mechanisms of spindle generation gleaned from animal studies, the mechanisms underlying certain features of spindles in the human brain, such as "global" versus "local" spindles, are largely unknown. Neither the topography nor the morphology of sleep spindles remains constant throughout the lifespan. It is likely that changes in spindle phenomenology during development and aging are the result of dramatic changes in brain structure and function.
Form and Function of Sleep Spindles across the Lifespan. Clawson BC, Durkin J, Aton SJ Neural Plast. 2016:6936381. doi: 10.1155/2016/6936381.

Complex complexity.Dionisio_{February 12, 2017
February
02
Feb
12
12
2017
07:30 AM
7
07
30
AM
PDT}

It is the persistence of twitching into adulthood, in humans and other mammals, that raises the intriguing possibility that twitching has much more to reveal to us about its functional contributions to neural plasticity within the sensorimotor system. If evidence of twitch-related spindle bursts is found, there will be a strong basis for expanding our understanding of the functions of spindle activity during non-REM sleep—about which we currently know a lot—to include REM sleep as well.
The Case of the Disappearing Spindle Burst Alexandre Tiriac and Mark S. Blumberg Neural Plast. 2016: 3467832. doi: 10.1155/2016/3467832

Complex complexity.Dionisio_{February 12, 2017
February
02
Feb
12
12
2017
07:21 AM
7
07
21
AM
PDT}

The cerebral cortex of mammals, including humans, displays oscillatory spindle activity (10–15?Hz) across the lifespan. In adults, sleep spindles, a specific type of spindle activity, occur exclusively during non-REM sleep [1–4] and have been implicated in memory retention and skill learning [5–7]. In humans, sleep spindles first appear 4–9 weeks postterm and become more prominent and frequent over the next several months [2]. There exists another type of spindle activity—called spindle bursts—that is phenomenologically similar to sleep spindles in that they share a similar frequency range, duration, and spindle-shaped waveform [8]. However, spindle bursts differ from sleep spindles in a variety of ways.
The Case of the Disappearing Spindle Burst Alexandre Tiriac and Mark S. Blumberg Neural Plast. 2016: 3467832. doi: 10.1155/2016/3467832

Complex complexity.Dionisio_{February 12, 2017
February
02
Feb
12
12
2017
06:06 AM
6
06
06
AM
PDT}

The more biology research papers get reviewed, it seems like the complex complexity is getting more complex, doesn't it? :)Dionisio_{February 12, 2017
February
02
Feb
12
12
2017
06:02 AM
6
06
02
AM
PDT}

Curiously, despite the persistence of twitching into adulthood, twitch-related spindle bursts have not been reported in adult sensorimotor cortex. This raises the question of whether such spindle burst activity does not occur in adulthood or, alternatively, occurs but has yet to be discovered. If twitch-related spindle bursts do occur in adults, they could contribute to the calibration, maintenance, and repair of sensorimotor systems.
The Case of the Disappearing Spindle Burst Alexandre Tiriac and Mark S. Blumberg Neural Plast. 2016: 3467832. doi: 10.1155/2016/3467832

Complex complexity.Dionisio_{February 12, 2017
February
02
Feb
12
12
2017
05:59 AM
5
05
59
AM
PDT}

Sleep spindles are brief cortical oscillations at 10–15?Hz that occur predominantly during non-REM (quiet) sleep in adult mammals and are thought to contribute to learning and memory. Spindle bursts are phenomenologically similar to sleep spindles, but they occur predominantly in early infancy and are triggered by peripheral sensory activity (e.g., by retinal waves); accordingly, spindle bursts are thought to organize neural networks in the developing brain and establish functional links with the sensory periphery.
The Case of the Disappearing Spindle Burst Alexandre Tiriac and Mark S. Blumberg Neural Plast. 2016: 3467832. doi: 10.1155/2016/3467832

Complex complexity.Dionisio_{February 12, 2017
February
02
Feb
12
12
2017
05:56 AM
5
05
56
AM
PDT}

Causal links from specific cellular mechanisms to oscillatory activity need to be established. Knowledge about NSB-related plasticity, especially, is still sparse.
Spindle Activity Orchestrates Plasticity during Development and Sleep Christoph Lindemann, Joachim Ahlbeck, Sebastian H. Bitzenhofer and Ileana L. Hanganu-Opatz Neural Plast. 2016: 5787423. doi: 10.1155/2016/5787423

Work in progress... stay tune. Complex complexity.Dionisio_{February 11, 2017
February
02
Feb
11
11
2017
08:48 PM
8
08
48
PM
PDT}

ASSs and NSBs represent distinct patterns of network synchronization in the adult and developing brain. While ASSs support memory consolidation through synchronous activation of large cortical areas, NSBs coordinate the maturation of local neocortical networks. Both patterns coordinate activity in sensory and limbic systems and modulate local plasticity critical for network refinement.
Spindle Activity Orchestrates Plasticity during Development and Sleep Christoph Lindemann, Joachim Ahlbeck, Sebastian H. Bitzenhofer and Ileana L. Hanganu-Opatz Neural Plast. 2016: 5787423. doi: 10.1155/2016/5787423

Complex complexity.Dionisio_{February 11, 2017
February
02
Feb
11
11
2017
08:45 PM
8
08
45
PM
PDT}

Information processing within the brain critically depends on rhythmic oscillatory activity that synchronizes neuronal networks. Synchronization leads to local and global coupling of network elements and times neuronal firing. By these means, it enables the precise selection of relevant information.
Spindle Activity Orchestrates Plasticity during Development and Sleep Christoph Lindemann, Joachim Ahlbeck, Sebastian H. Bitzenhofer and Ileana L. Hanganu-Opatz Neural Plast. 2016: 5787423. doi: 10.1155/2016/5787423

Complex complexity.Dionisio_{February 11, 2017
February
02
Feb
11
11
2017
08:42 PM
8
08
42
PM
PDT}

Spindle oscillations have been described during early brain development and in the adult brain. Besides similarities in temporal patterns and involved brain areas, neonatal spindle bursts (NSBs) and adult sleep spindles (ASSs) show differences in their occurrence, spatial distribution, and underlying mechanisms.
Spindle Activity Orchestrates Plasticity during Development and Sleep Christoph Lindemann, Joachim Ahlbeck, Sebastian H. Bitzenhofer and Ileana L. Hanganu-Opatz Neural Plast. 2016: 5787423. doi: 10.1155/2016/5787423

Complex complexity.Dionisio_{February 11, 2017
February
02
Feb
11
11
2017
08:40 PM
8
08
40
PM
PDT}

[...] neuronal activity impacts the development and integration of cortical interneurons, by influencing their migration and maturation [...] [...] activity-dependent transcription programs control the electrophysiological properties and output of mature interneurons. [...] a complex, dynamic interplay between intrinsic genetic programs and environmental influences shape cortical circuits from early developmental stages into adulthood. [...] it is of high importance to determine the factors regulating interneuron maturation [...]
Neuronal activity controls the development of interneurons in the somatosensory cortex Rachel Babij and Natalia De Marco Garcia Front Biol (Beijing). 11(6): 459–470. doi: 10.1007/s11515-016-1427-x

Did somebody say "programs"? :) Complex complexity.Dionisio_{February 10, 2017
February
02
Feb
10
10
2017
07:43 AM
7
07
43
AM
PDT}

[...] neuronal activity is required for the proper regulation of GABA expression in mature interneurons. [...] the expression of GABA-synthesizing enzymes, glutamic acid decarboxylase (GAD) ?65 and 67, is also activity dependent [...] [...] activity can influence interneuron output even after these neurons become integrated into the mature circuit.
Neuronal activity controls the development of interneurons in the somatosensory cortex Rachel Babij and Natalia De Marco Garcia Front Biol (Beijing). 11(6): 459–470. doi: 10.1007/s11515-016-1427-x

Complex complexity.Dionisio_{February 10, 2017
February
02
Feb
10
10
2017
07:39 AM
7
07
39
AM
PDT}

[...] cortical activity can trigger changes in intrinsic properties in the adult animal. [...] Er81, a member of the ETS family of transcription factors that delineates PV interneurons in layers II/III, is required for the modulation of their intrinsic properties in mature animals. It would be interesting to assess whether the expression of genes that confer interneurons with subtype identity are also subject changes in neuronal excitability.
Neuronal activity controls the development of interneurons in the somatosensory cortex Rachel Babij and Natalia De Marco Garcia Front Biol (Beijing). 11(6): 459–470. doi: 10.1007/s11515-016-1427-x

Complex complexity.Dionisio_{February 10, 2017
February
02
Feb
10
10
2017
07:20 AM
7
07
20
AM
PDT}

Development of neocortical areas follows a defined sequence in which excitatory and inhibitory neurons, generated in the dorsal and ventral telencephalon respectively, migrate to their final locations [...] As they mature, neurons participate in nascent electrical patterns, and ultimately extend dendritic and axonal branches to form functional connections. During these periods, proper development is dependent not only on genetic patterns and progression of intrinsic programs, but also on the activity of input connections [...]
Neuronal activity controls the development of interneurons in the somatosensory cortex Rachel Babij and Natalia De Marco Garcia Front Biol (Beijing). 11(6): 459–470. doi: 10.1007/s11515-016-1427-x

Did somebody say "programs"? :) Complex complexity.Dionisio_{February 10, 2017
February
02
Feb
10
10
2017
07:08 AM
7
07
08
AM
PDT}

Neuronal activity shapes the developmental assembly of functional circuitry in the somatosensory cortical interneurons. This activity impacts nearly every aspect of development and acquisition of mature neuronal characteristics, and may contribute to changing phenotypes, altered transmitter expression, and plasticity in the adult. Progressively changing oscillatory network patterns contribute to this activity in the early postnatal period, although a direct requirement for specific patterns and origins of activity remains to be demonstrated.
Neuronal activity controls the development of interneurons in the somatosensory cortex Rachel Babij and Natalia De Marco Garcia Front Biol (Beijing). 11(6): 459–470. doi: 10.1007/s11515-016-1427-x

Complex complexity.Dionisio_{February 9, 2017
February
02
Feb
9
09
2017
09:26 PM
9
09
26
PM
PDT}

[...] it is unclear to what extent and how this activity connects to other cortical and subcortical regions [...] [...] it remains to be studied whether the immature brain shows a spindle burst related “resting state” and how this network state is altered by sensory activation or by pathophysiological events. [...] it would be most interesting and important to correlate specific patterns of spontaneous activity (e.g., delta brush) recorded by means of full-band direct-current EEG in preterm und full-term human neonates with the acute functional state and with the further development of the child [...]
Spindle Bursts in Neonatal Rat Cerebral Cortex. Yang JW, Reyes-Puerta V, Kilb W, Luhmann HJ Neural Plast. 2016;2016:3467832. doi: 10.1155/2016/3467832 .

Complex complexity.Dionisio_{February 9, 2017
February
02
Feb
9
09
2017
09:10 PM
9
09
10
PM
PDT}

Network-driven spindle-like oscillations are a functional hallmark of the developing cerebral cortex. [...] it remains an open question whether the specific properties of spindle burst are required or fulfill a distinct role in development. [...] the role of GABAergic synaptic activity during spindle bursts is currently unclear. [...] it is tempting to speculate that spindle bursts control the spatially confined release of GABA in developing local networks.
Spindle Bursts in Neonatal Rat Cerebral Cortex. Yang JW, Reyes-Puerta V, Kilb W, Luhmann HJ Neural Plast. 2016;2016:3467832. doi: 10.1155/2016/3467832.

Complex complexity.Dionisio_{February 9, 2017
February
02
Feb
9
09
2017
09:00 PM
9
09
00
PM
PDT}

[...] it is reasonable to suggest that spindle bursts represent the network correlate of NMDA receptor mediated activity-dependent plasticity in the developing cortex. In the adult, SWA is a prominent pattern activity seen during sleep or light sedation. In the developing brain, spindle bursts are the dominant feature of sleep activity. The precise roles for spindle bursts remain unclear, but their contribution in synaptogenesis and circuit connectivity is unquestionable. [...] the independence of these patterns is a key message regarding the spontaneous activity of the brain. We believe it is neither noise nor a wasteful consequence of brain structure; it is an useful activity, purposefully generated, and used for specific and definable purposes.
Large Scale Cortical Functional Networks Associated with Slow-Wave and Spindle-Burst-Related Spontaneous Activity David A. McVea, Timothy H. Murphy and Majid H. Mohajerani Front Neural Circuits. 10: 103. doi: 10.3389/fncir.2016.00103

Complex complexity.Dionisio_{February 9, 2017
February
02
Feb
9
09
2017
07:34 PM
7
07
34
PM
PDT}

Cortical sensory systems are active with rich patterns of activity during sleep and under light anesthesia. Remarkably, this activity shares many characteristics with those present when the awake brain responds to sensory stimuli. While the sleep-related functions of both slow-wave and spindle-burst activity may not be entirely clear, they reflect robust regulated phenomena which can engage select wide-spread cortical circuits. These circuits are similar to those activated during sensory processing and volitional events. [...] prominent and well-studied forms of spontaneous activity that will yield valuable insights into brain function in the coming years.
Large Scale Cortical Functional Networks Associated with Slow-Wave and Spindle-Burst-Related Spontaneous Activity David A. McVea, Timothy H. Murphy and Majid H. Mohajerani Front Neural Circuits. 10: 103. doi: 10.3389/fncir.2016.00103

Complex complexity.Dionisio_{February 9, 2017
February
02
Feb
9
09
2017
07:03 PM
7
07
03
PM
PDT}

More statistics will make it possible to build more explicit models of Bicoid dependent activation. [...] the precision in determining the position of the nuclei is not only encoded in the time averaged gene readout, but probably relies either on spatial averaging mechanisms [...] or more detailed features of the temporal information encoded in the full trace [...] [...] transcription is a bursty process with relatively large inter-nuclei variability, suggesting that simply the templated one to one time-averaged readout of the Bicoid gradient is unlikely. Comparing mutant experiments can shed light on exactly how the decision to form the sharp hunchback mRNA and protein boundary is made.
Precision of Readout at the hunchback Gene: Analyzing Short Transcription Time Traces in Living Fly Embryos Jonathan Desponds, Huy Tran, Teresa Ferraro, Tanguy Lucas, Carmina Perez Romero, Aurelien Guillou, Cecile Fradin, Mathieu Coppey, Nathalie Dostatni, Aleksandra M. Walczak PLoS Computational Biology 12(12): e1005256. DOI: 10.1371/journal.pcbi.1005256

Complex complexity.Dionisio_{February 9, 2017
February
02
Feb
9
09
2017
04:27 PM
4
04
27
PM
PDT}

[...] mRNAs are generally produced in bursts, which result from periods of activation and inactivation. [...] the promoter has distinct periods of enhanced polymerase transcription followed by identifiable periods of basal polymerase activity. [...] the promoter states cycle through at least three states [...] In one of these states the polymerase transcribes at enhanced levels, while in most of the remaining states the transcription machinery gets reassembled or the chromatin remodels. [...] independently of the question of the nature of the bursts, it would be very interesting to see whether and how it changes when the nature of regulation changes.
Precision of Readout at the hunchback Gene: Analyzing Short Transcription Time Traces in Living Fly Embryos Jonathan Desponds, Huy Tran, Teresa Ferraro, Tanguy Lucas, Carmina Perez Romero, Aurelien Guillou, Cecile Fradin, Mathieu Coppey, Nathalie Dostatni, Aleksandra M. Walczak PLoS Computational Biology 12(12): e1005256. DOI: 10.1371/journal.pcbi.1005256

Complex complexity.Dionisio_{February 9, 2017
February
02
Feb
9
09
2017
04:26 PM
4
04
26
PM
PDT}

[...] the initial mRNA readout of the maternal Bicoid gradient by the hunchback gene is remarkably accurate and reproducible between embryos [...] [...] it is highly expressed in the anterior part of the embryo, quickly decreasing in the middle and not expressed in the posterior part. This precision is even more surprising given the very short duration of the cell cycles (6±15 minutes) during which the initial Bicoid readout takes place and the intrinsic molecular noise in transcription regulation [...]
Precision of Readout at the hunchback Gene: Analyzing Short Transcription Time Traces in Living Fly Embryos Jonathan Desponds, Huy Tran, Teresa Ferraro, Tanguy Lucas, Carmina Perez Romero, Aurelien Guillou, Cecile Fradin, Mathieu Coppey, Nathalie Dostatni, Aleksandra M. Walczak PLoS Computational Biology 12(12): e1005256. DOI: 10.1371/journal.pcbi.1005256

remarkably accurate? hmm... This precision is even more surprising? precision? surprising? why surprising? Complex complexity.Dionisio_{February 9, 2017
February
02
Feb
9
09
2017
02:38 PM
2
02
38
PM
PDT}

#2776 error correction: The word "different" was misspelled.Dionisio_{February 9, 2017
February
02
Feb
9
09
2017
02:03 PM
2
02
03
PM
PDT}

The same paper referenced @1404 & @1560.

Only accessible information is useful: insights from gradient-mediated patterning Mikhail Tikhonov, Shawn C. Little, Thomas Gregor DOI: 10.1098/rsos.150486 http://rsos.royalsocietypublishing.org/content/2/11/150486

Dionisio_{February 9, 2017
February
02
Feb
9
09
2017
01:51 PM
1
01
51
PM
PDT}

Prev 1 … 22 23 24 25 26 … 117 Next

You must be logged in to post a comment.

Leave a Reply