Excellent B Standard, Olive ran in 67.09 (SCT 76). Not a good course for us - starting and ending with a line of offset jumps - but Olive had a good run, particularly after the weaves. In fact, so fast that she almost took a wrong course tunnel on me. 3rd place.

Olive's time on the Jumpers course was 47.62 (SCT 50). A better start for our last run of the year, my timing was a little off heading into a tunnel and almost cost us a Refusal but Olive drove on and earned 4th place.

After a couple of days doing Field Trials, it was good to turn in some nice agility runs. My handling was a little sloppy but Olive was driven. Lifetime, this was Olive's 31st Double Q!

Olive became a Master Agility Champion in 2012

Harvard scientists are shedding light on a neural feedback mechanism that may play a key role in how the olfactory system works in the brain. The mechanism was first identified more than a century ago, but little was understood about its workings till now.

As described in a Dec. 19 paper in Neuron by Venkatesh Murthy, a professor of molecular and cellular biology, researchers have, for the first time, described how that feedback mechanism works by identifying where the signals go, and which type of neurons receive them. Three scientists from the Murthy lab were involved in the work: Foivos Markopoulos, Dan Rokni, and David Gire.

“The image of the brain as a linear processor is a convenient one, but almost all brains, and certainly mammalian brains, do not rely on that kind of pure feed-forward system,” Murthy said. “On the contrary, it now appears that the higher regions of the brain, which are responsible for interpreting olfactory information, are communicating with lower parts of the brain on a near-constant basis.”

The mechanism’s precise workings remained a mystery in part because the technological tools needed to activate individual neurons and individual pathways simply weren’t available.

“One of the challenges with this type of research is that these feedback neurons are not the only neurons that come back to the olfactory bulb,” Murthy explained. “The challenge has always been that there’s no easy way to pick out just one type of neuron to activate.”

To do it, Murthy and his team turned to a technique called optogenetics.

Using a virus that has been genetically modified to produce a light-sensitive protein, Murthy and his team marked specific neurons, which become active when hit with laser light. Researchers were then able to trace the feedback mechanism from the brain’s processing centers back to the olfactory bulb.

Reaching that level of precision was critical, Murthy explained, because while the olfactory bulb contains many “principal” neurons that are responsible for sending signals to other the parts of the brain, it is also packed with interneurons, which appear to play a role in formatting olfactory information as it comes into the brain.

Without that formatting process, Murthy said, the brain would likely have trouble interpreting the wide range of signals — from very weak to very strong — it encounters.

“If you make a system that is very good at detecting weak signals, it becomes saturated as the signal gets stronger, and eventually it’s impossible to differentiate between strong signals,” Murthy said. “To avoid that problem, brain circuits use a process called gain control. By inhibiting certain neurons, it ensures that you stay within the detection range, so you don’t miss the weak things, but you don’t miss the very strong things either.”

Earlier studies had hinted that the interneurons in the olfactory bulb are the primary target of the feedback signals, but Murthy’s study is the first to prove it, and to show that those feedback signals effectively inhibit the activity of the principal neurons.

“When the cortical area decides to send these signals back to the olfactory bulb, it’s effectively turning down the activity of these principal neurons,” Murthy said. “Why does the brain do this? Our theory is that the feedback is a way for the cortex to say, ‘I heard you.’ As the olfactory information is sent to higher regions of the brain, these signals come back and turn down the volume on the input.”

While similar systems have been identified in other parts of the brain, the extent of the olfactory feedback was surprising. Murthy’s research showed that the system doesn’t simply send signals back to the olfactory bulb, but sends them to its very first layer of neurons.

“That feedback is coming back to the very first synapse, if you will,” he said.

Even more surprising, Murthy said, was evidence that the olfactory bulb’s principal neurons were also receiving feedback signals — albeit weak ones — that appeared to prime them for incoming signals.

“These weak connections help the principal neuron get over the top when it’s listening to weak inputs,” Murthy said. “If there’s a weak smell coming in, but it’s not able to drive the principal neuron over the threshold to signal the rest of the brain, but say you’re in an environment where you’re primed to smell that weak smell — we believe this feedback from this higher area of the brain is sort of tickling these principal neurons, so when there’s a weak input you’re able to smell it.

“For most animals, smell is a very, very important thing,” Murthy added. “If they are in an environment where there’s one overwhelming smell that’s irrelevant, they need to be able to detect a weak smell that may signal danger. We are hypothesizing that this mechanism, where the cortex is talking back to the olfactory bulb and suppressing neurons, through this feedback they may be able to detect that weak signal.”

I took a track on Christmas Eve during the afternoon for my cousin's good friend. I called my brother in law Andre where he could get his new pup Aleah some OJT.

Hunter's Story
The shot was about 250 yards on a broadside buck standing. At the shot the buck hit the ground then jumped up and ran to the thickest stuff you can walk in. They had good blood that they tracked for 150 yards. Hunters also reported seeing some corn stuff in the blood.

What we found
The shot site was down a gravel/ grass road. We drove in our trucks followed the hunter to the shot site. When we got ready to go to the hit site, I looked down and saw, quite by accident, a drop of blood under my truck. Hunter said....Oh yea, After the deer was shot, fell down and jumped back up....it ran that way and then turned away and ran fifty yards before cutting into the woods. Tasha checked the hit site and found nothing. Tasha took us to the cutover which may be the worse briers that I have ever been in. Andre and Aleah were also working the blood trail we found here. The trail was lite drops of blood scattered along with a few small waist high smears on grass. There were two small areas about the size of saucers where the deer had stood and dripped blood. We only found blood for 60 yards when I checked the GPS.  Tasha took the track about two hundred yards but I never saw any indication other than a very deep track along this trail.  We never saw any corn or any other indication of gut shot. We started over, walked the perimeter and even tracked blindly down deer trails. They was no wind blowing but when we did get a breeze, Tasha raised her nose and sampled the air for 20 seconds or so. I made sure that we spent some time checking this area out thoroughly. After over two hours of thick thick cutover tracking, we were not able to advance the track.

Learnings for us:
- don't park in you hit site.
- do a complete interview of the hunter.....I didn't do a complete interview over the phone because I knew that I was taking this call regardless. I am still not sure if the hunter shot once or twice. This was a new bullet for his rifle that had not been sighted in prior to the hunt. I probably still don't have all the pieces of the puzzle.
- a good pair of brier pants, brier jacket and brier gloves are worth the investment.

Well, we didn't find the deer. I believe it was hit high because of the blood smears it left high on the grass and the fact that it dropped instantly but then jumped up and regained his composure. They will watch this area for buzzards. It is right by his house. I mailed him the GPS track analysis with areas of concern highlighted on it. They will let us know if they find out anything else. The hunter also shared some homemade pickled okra, homemade salsa and homemade hot pepper jelly with us. Another fun outing. Tasha and Aleah crashed all the way back home.

Diane asked me on the drive home whether I thought Olive or Asti had a better weekend.  It was an interesting question.  I think Olive's second series run yesterday was probably the most impressive run of the two days, with Asti's first series today a close second and Asti's fourth series run in third.  I'm not sure either was clearly better than the other - I think both girls are really talented, Asti more naturally and Olive more skilled.  I love running them both, although I probably favor Asti slightly from the bond we formed over our years of hunting together.  I wouldn't trade either for the world!