In a research lab in East Baltimore, rats that provide clues to how the brain degenerates with age could grow too old or even die before scientists can complete their experiments.

At a homeless shelter, a Baltimore mother feeds her underweight toddler cereal, peanut butter and milk — and worries about nutrition aid running out before the child reaches a healthier size.

In his Reisterstown home, a veteran hobbled by injuries stemming from his Army service decades ago waits for a check to help offset medical bills.

As the federal government shutdown continues into another week, Marylanders are feeling the impact from the funding and services that have been cut or threatened. The state is home to about 300,000 federal employees, and wide-ranging furloughs at the Social Security Administration headquarters in Woodlawn, the National Institutes of Health in Bethesda and other workplaces make the effects of the shutdown particularly broad. Here's a look at some state residents feeling the pinch:

Jeff Mayse, behavioral neuroscience researcher

The federal government might sputter to a halt, but Jeff Mayse's rats continue to age.

They'll do it, though, away from the watchful eyes of the 26-year-old Mayse and his colleagues at a National Institute of Aging lab, among the many federally funded research programs halted as of Tuesday.

At the lab, located on the Bayview medical campus in East Baltimore, Mayse conducts cognition experiments on older rats — making time of the essence.

"It's a very small window," Mayse says of the 24- to 27-month-old span during which the rats are old enough to show age-related brain deficits but still healthy enough to perform the tasks he creates for them. "We don't even know how long this shutdown will last. We could have old animals that will die."

Technicians remain on site to feed the animals, but even a short interruption means the rats could forget the complicated tasks Mayse has taught them as a way of testing their ability to adapt responses to different stimuli.

"It's so massively disrupting," he said. "This is scientific research, and we're cutting off experiments in the middle."

Mayse, who is working on a doctorate at the Johns Hopkins University, focuses on the basal forebrain, which in humans is where degeneration occurs in patients with Alzheimer's and dementia. His research has implications for better understanding such diseases and perhaps finding ways to restore lost brain functions.

He and his colleagues — there are nine in the lab — represent just a fraction of the research that has been halted because of the shutdown: The NIA is one of 27 institutes and centers that make up the National Institutes of Health, the federal agency that is the world's largest funder of medical research.

The shutdown comes on the heels of some 10 years of flat funding, followed by a 5.5 percent cut earlier this year as mandated by sequestration, according to the NIH.

"It's always something," Mayse said. "Sequestration hit us really hard. It's creating a very difficult environment for what are already very difficult experiments."

Mayse has used the unwelcome time off to visit his wife, also a neuroscientist, who recently started postdoctoral work at Brown University in Providence, R.I. He's also had more time to write his thesis for the doctorate he hopes to complete next summer, though that, too, could be delayed.

"I do have more time to write," Mayse said, "but what I really need is to collect new data from the animals."

Lauren Nivens, mother of two

At a recent child wellness visit at Health Care for the Homeless, Lauren Nivens learned that her 15-month-old daughter, Morgan Carolina, isn't growing as quickly as she should. The child is underweight at just 17 pounds, her pediatrician says, and only 30 inches tall.

So to Nivens, the milk, bread, peanut butter and other foods she receives free through a federal program to feed the child have become even more crucial — at the same time that her continued access to them is in jeopardy.