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Record W1999815031 · doi:10.1139/z05-171

Physiology of coordination in sponges

2006· article· en· W1999815031 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

venuePublished in a venue whose home country is Canada.
no affNo Canadian affiliation: this work is invisible to an affiliation-only frame.
No Canadian affiliation. An affiliation-only frame, the usual design, would never have seen this work. It is one of the works that make the case for inverting the frame.

Bibliographic record

VenueCanadian Journal of Zoology · 2006
Typearticle
Languageen
FieldBiochemistry, Genetics and Molecular Biology
TopicMarine Sponges and Natural Products
Canadian institutionsnot available
Fundersnot available
KeywordsBiologyMulticellular organismSecond messenger systemNervous systemIntracellularStimulationNeuroscienceSpongeCell biologyCellBotanyBiochemistry

Abstract

fetched live from OpenAlex

All multicellular organisms need a means of communicating between cells and between regions of the body. The evolution of a nervous system, by the Cnidaria, provided a fast means of communication and enabled the colonization of rapidly changing environments. Sponges, the descendants of the first multicellular animals, lack nerves but nevertheless have a number of different systems that allow coordinated behaviour, albeit rather slow coordinated behaviour. It is from elements within these systems that the origins of the nervous and endocrine systems, the grand organizing principles of higher animals, seem likely to have appeared. Electrical activity has not been found in cellular sponges, yet local contractions are elicited in response to a variety of stimuli and, in some cases, contractions propagate across the body to control the hydrodynamics of the feeding current. The mechanism of propagation is thought to involve hormones or a combination of other signaling molecules and direct mechanical action of one cell on the next, leading to increased intracellular calcium. In other instances cellular sponges respond to stress, such as heat shock, by elevating intracellular calcium by way of second messengers such as cyclic ADP-ribose. Electrical communication, well known in plants and protists, was first demonstrated in a sponge in 1997. Hexactinellids (glass sponges), which arrest their feeding current within 20 s of mechanical or electrical stimulation, do so via an electrical impulse that propagates through syncytial tissues. These unusual syncytial tissues are cytoplasmically coupled from outside to inside and top to bottom so that there are no membrane boundaries to impede the electrical currents. Pharmacological tests suggest that Ca 2+ , rather than Na + , drives the action potential. The conduction velocity is slow (0.27 cm·s –1 ) and is highly temperature sensitive (Q 10 ~3). At present, glass sponges are the only poriferans known to have propagated electrical signals. In addition, reports of directional swimming in sponge larvae, of the rapid and coordinated changes in the tensile strength of the extracellular matrix in Chondrosia Nardo, 1847, and of the rapid closure of ostia of some cellular sponges in response to mechanical stimuli further illustrate the variety of coordinating mechanisms that evolved in the Porifera in the absence of a nervous system.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.767
Threshold uncertainty score0.933

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.004
GPT teacher head0.201
Teacher spread0.197 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it